Redistricting with 2020 Population Estimates (and 2016/2018 Political Data)

[Former Dean Phillips Supporters for Haley (I guess???!?) 👁️]

In this thread I will look at 2020 redistricting using 2020 population estimates that I made, and also for some states using estimated precinct election results data for 2016 and 2018 elections.

The population estimates can be used directly in Dave's Redistricting App, and I will upload the files with the 2020 data in this thread so that other people can try out the 2020 data as well.

So far I have only done this for a few states. I probably won't bother to do this for literally every single state, but will at least do so for some of the more interesting states where population changes (and perhaps changes in control over redistricting) could make a significant difference. If anyone has a few particular requests for states, I will try to do those states.

The political data estimates so far only consist of Clinton-Trump precinct results for Illinois. Later I will probably add 2018 Senate Beto-Cruz precinct result estimates for TX, 2018 Governor Abrams-Kemp estimates for GA, and Clinton-Trump estimates for NY (maybe something else if I feel like it). For an explanation of how the precinct estimates are made, see this post.

For more 2020 population estimates for more states, see this thread by cvparty.


How I made these estimates

I took 2017 census population estimates and assumed that the same growth rate that has been estimated for 2011-2017 by the census will continue in 2018-2010 to calculate estimated population totals for 2020. These growth rates are then applied equally to the entire population within each county, across all precincts and to all racial groups. I did not do anything to update VAP data, and since this applies the same growth rate to all racial groups, it will not reflect greater-than-average minority population growth.

Projected 2020 race data for some states

However, for a few states I have made the extra effort to incorporate 2020 race data estimates. This is mostly in states where the Voting Rights Act is a particularly important consideration. I did this by combining the 5-year American Community Survey estimates of Race by Hispanic Origin for 2012-2016 with Census county total population estimates for 2017. The way I did this was to project the total population in each county as with other states, using the 2017 population estimates, and then assume that the distribution of growth by race and Hispanic origin within each county would match the distribution of growth from 2010 to the 2012-2016 ACS estimates (which on average can be thought of as 2014 estimates). The same overall growth rate for each racial group is applied to each precinct within each county, which means that population growth for each racial group is assigned within each county in proportion to the 2010 population for each racial group in that county.

So far, states with this race data are: Georgia



How to use these estimates

1) Find the folder where Dave's Redistricting App stores data on your computer. This may be located in a different place depending on your computer's operating system. If you are not sure where to find this, the help page here at DRA may help (look under "saved files"). For example, for me (using Windows 10) this folder is located here for Virginia:

C:\Users\Laptop\AppData\LocalLow\Microsoft\Silverlight\is\tdttpzju.v3n\j44hdtyb.0sj\1\s\mbcuc5y11hatden4rfah5rjgwlpl3hes2ogfqs2jqmkdx103loaaadaa\f\DavesRedistrictingFiles\Virginia

2) Back up your original DRA files. My 2020 population estimates will overwrite the original 2010 census data, so back up your files to make sure you can go back to the 2010 data.

3) Download my 2020 population estimates for the state you are interested in from the link below.

Iowa 2020 Population Estimates DRA File
Georgia 2020 Population Estimates DRA File
Texas 2020 Population Estimates DRA File
Virginia 2020 Population Estimates DRA File

4) When you download the file, you will need to rename it to remove a "_2020estimates" that I added to the filename. For example, for Virginia my file is named "vt51_data_2020estimates.csv". So rename that to "vt51_data.csv". Then copy it into the DRA folder for the relevant state to replace the original "vt51_data.csv" folder that DRA originally downloaded (again, be sure to back up your original file first before replacing it with my new data file).

5) If you have problems restoring the original 2010 census data later, you can always delete your entire DRA folder for that state, and then DRA will re-download the original 2010 census data files the next time you load the state.



Political Data

Illinois 2016 President Precinct Results Estimates DRA File

To use the Political Data, you just do the same thing as with the Population Estimates data - just overwrite your existing file that DRA saves to your computer.



I will keep this original post updated with links for data for new states as I add them.

[Former Dean Phillips Supporters for Haley (I guess???!?) 👁️]

Now, I will post some maps I made using the data for Virginia. I was primarily interested in what a Democratic gerrymander might look like if the Supreme Court does not rule against partisan gerrymandering and if Democrats gain control over redistricting in Virginia, and also in what a neutral map might look like.

I was particularly interested in the question of how many Democratic seats NOVA could support, and what sorts of PVI they would have (whether they would be safe seats or not), following from a map that Mizzouian posted (an 8-3 Democratic gerrymander, but one where not all the Democratic seats are very safe and one of them is really a swing seat).

As it turns out, thanks to a combination of the population shift towards NOVA and also Republican self-packing in Appalachia (and to a lesser extent the Richmond exurbs), it is possible to make not just an 8-3 Democratic gerrymander, but actually a 9-2 Democratic gerrymander. This is a no-holds-barred gerrymander, similar to the sort of gerrymander drawn by Ohio Republicans and North Carolina Republicans. At least if one does not make an Arlington-Alexandria Democratic vote sink, NOVA can actually support about 4.5 Democratic districts.

This means that you can have 4 districts safely Democratic based only upon Dem votes in NOVA, but for a 5th district you need to combine parts of NOVA with some Democratic voting areas elsewhere - the only real candidates for that are either Charlottesville or the Richmond suburbs. The main difficulty in drawing a 9-2 Democratic map lies in combing the self-packing Republicans in Appalachia and the Shenandoah with the self-packing Republican cluster around Richmond, while also contiguously combining that 5th NOVA seat with either Charlottesville or with Richmond.

This is a problem that must be overcome, at least if one wants all the districts in NOVA to have solidly Democratic PVIs, because the GOP Richmond exurbs (places like 63% Trump Hanover county) are just a little bit too much for the NOVA districts to swallow without making at least one NOVA district competitive.

The other challenge is in making a safely Democratic seat centered on Charlottesville. It is pretty easy to make this a swing district, but much harder to make it safely Democratic. In order to be safely Democratic, this seat must either include some Democratic voters in NOVA or in the Richmond area, both of which threaten to block contiguity between the Republican Appalachia cluster and the Republican Richmond exurbs cluster.

The best configuration I have found to do this so far is this one:


9-2 Dem Gerrymander







VA-01 (blue) - D+6.7, 57.1%-42.1% Obama '08
VA-02 (dark green) - D+3.8, 55.7%-43.5% Obama '08
VA-03 (purple) - D+7.4, 59.0%-40.3% Obama '08
VA-04 (red) - D+7.5, 57.3%-42.0% Obama '08
VA-05 (yellow) - D+5.2, 57.2%-41.9% Obama '08
VA-06 (teal) - R+20.2, 65.4%-33.7% McCain '08
VA-07 (gray) - D+6.7, 57.2%-41.9% Obama '08
VA-08 (slate blue) - D+6.6, 57.1%-42.1% Obama '08
VA-09 (light blue) - R+22.6, 61.6%-37.0% McCain '08
VA-10 (pink) - D+6.9, 57.8%-41.3% Obama '08
VA-11 (light green) - D+6.4, 55.0%-44.2% Obama '08

The PVI of VA-02 is a bit lower than one might like for a Democratic gerrymander, but I don't think it is possible to do substantially better without reducing Black voters' control over VA-03. As drawn, VA-03 is 38.7% black and 51.1% white (based off of 2010 race data, so with 2020 data it would surely be majority-minority), which is about the same as the current VA-03.

The main point of potential controversy here is VA-04, which is centered more on Richmond than the actual current VA-04. I originally tried making VA-04 be a compact purely Richmond district, but the problem with that is it ends up at about D+12 and wastes Democratic votes - meanwhile that leaves VA-05 competitive, rather than fairly safe or at least strongly Dem leaning (D+5). So I extended an arm of VA-05 into Richmond to pick up the white liberal areas of central Richmond.

With 2010 race data, this VA-04 is 51.8% white, 34.7% black, 6.8% hispanic, 4.2% asian. So it would be majority-minority with 2020 data. By comparison, the current VA-04 is 51.5% white, 41.1% black. So this district has somewhat fewer, but basically the same overall minority population. Despite the slightly lower black population, black voters' control of the district may actually be increased, because the white liberal areas of Richmond are put in VA-05, so black voters may actually even make up a greater share of Democratic primary voters.

An alternative configuration is to have VA-05 include Charlottesville rather than part of Richmond, but then the problem is contiguity for VA-06. This also doesn't do anything to make the PVI of VA-05 more Democratic.



Alternative 9-2 Dem Gerrymander

If the reduction in the black population (and increase in the non-black minority population) in VA-04 is not acceptable to the VRA, I made an alternative 9-2 map. In this map, VA-04 is more similar to the current district, and rather than having the 5th NOVA seat combine Charlottesville with part of NOVA, the 5th NOVA seat combines part or the Richmond suburbs with NOVA. Meanwhile, VA-05 combines Charlottesville with another part of the Richmond suburbs.

The main benefit of this alternative map is that VA-04 is more similar to the current district, and there is no possibility of VRA issues. The main downside is that several of the Democratic districts are a bit less safe. The change in PVI relative to the first map is shown in parentheses:







VA-01 (blue) - D+5.7 (-1), 55.9%-42.1% Obama '08
VA-02 (dark green) - D+3.7 (-.1), 55.5%-43.7% Obama '08
VA-03 (purple) - D+6.4 (-1), 58.0%-41.3% Obama '08
VA-04 (red) - D+6.7 (-.8 ), 58.7%-40.5% Obama '08
VA-05 (yellow) - D+4.8 (-.4), 55.8%-43.3% Obama '08
VA-06 (teal) - R+20.8 (+.6), 62.3%-36.6% McCain '08
VA-07 (gray) - D+6.8 (+.1), 56.2%-43.0% Obama '08
VA-08 (slate blue) - D+6.7 (+.1), 56.9%-42.3% Obama '08
VA-09 (light blue) - R+18.8 (-2.8 ), 63.0%-35.8% McCain '08
VA-10 (pink) - D+6.6 (-.3), 57.5%-41.6% Obama '08
VA-11 (light green) - D+6.9 (+.5), 56.3%-42.9% Obama '08


As you can see, most of the Democratic districts are a fraction of a point to a point less Democratic. Either I just did a worse job in making the districts Democratic in this map, or else this configuration (NOVA to Richmond district rather than NOVA to Charlottesville) simply results in a less efficient distribution of votes. So personally I prefer the first configuration, as long as lowering the black population in VA-04 (but keeping the overall minority population the same) is acceptable for VRA purposes.



Next, here is an 8-3 Dem Gerrymander.

8-3 Dem Gerrymander







VA-01 (blue) - R+13.4, 58.0%-41.1% McCain '08
VA-02 (dark green) - D+3.7, 55.5%-43.7% Obama '08
VA-03 (purple) - D+6.4, 58.0%-41.3% Obama '08
VA-04 (red) - D+6.7, 58.7%-40.5% Obama '08
VA-05 (yellow) - D+8.1, 57.9%-41.3% Obama '08
VA-06 (teal) - R+19.1, 63.0%-36.0% McCain '08
VA-07 (gray) - D+9.3, 57.6%-41.6% Obama '08
VA-08 (slate blue) - D+9.0, 59.5%-39.7% Obama '08
VA-09 (light blue) - R+16.6, 56.7%-41.9% McCain '08
VA-10 (pink) - D+10.3, 60.0%-39.2% Obama '08
VA-11 (light green) - D+9.2, 57.6%-41.6% Obama '08

This actually makes VA-05 safer than VA-04, so I should probably switch some voters between those two districts.

In my opinion, this is just wasting votes. It makes the NOVA districts even safer, but it doesn't do anything to help the most vulnerable Democratic district (VA-02). It does make the map look a bit cleaner, but it still is obviously gerrymandered. It would still get just as bad press as a 9-2 map, but for worse results (from a D partisan perspective). So in my opinion, if you are going to gerrymander, you may as well do it properly and go for a 9-2 map.

With a 9-2 map, is it possible that Republicans might temporarily pick up 1 or 2 of the D+5 to D+7 districts in a really good GOP wave year? Sure. But if so, Republicans would be winning by enough nationally that they would definitely win control of Congress anyway, and the seats could be won back in the first non-GOP wave year.



Finally, here is a neutral non-partisan map. If the Supreme Court rules against partisan gerrymandering and we have a truly level playing field nationwide, we might hope to get a map that is something like this.

Non-Partisan map (leaning 6-5 with some competitive districts)



VA-01 (blue) - R+3.2, 51.0%-48.3% McCain '08
VA-02 (dark green) - D+3.2, 55.0%-44.1% Obama '08
VA-03 (purple) - D+7.2, 58.6%-40.7% Obama '08
VA-04 (red) - D+6.2, 56.8%-42.5% Obama '08
VA-05 (yellow) - R+5.2, 50.6%-48.5% McCain '08
VA-06 (teal) - R+20.3, 59.5%-39.2% McCain '08
VA-07 (gray) - R+2.7, 50.1%-49.1% Obama '08
VA-08 (slate blue) - D+21.7, 68.6%-30.6% Obama '08
VA-09 (light blue) - R+13.0, 56.6%-42.3% McCain '08
VA-10 (pink) - D+7.2, 56.5%-42.8% Obama '08
VA-11 (light green) - D+9.7, 57.2%-42.0% Obama '08

Unlike the Democratic gerrymanders above, this map is fairly well reflective of Virginia's actual politics. There are 6 districts that lean or are safe D, and 5 that lean or are safe R. On both sides, there are 1 or 2 competitive districts that could go the other way than their lean, especially VA-01, VA-02, and VA-07, but maybe also VA-04 and VA-05 in wave years.

[Former Dean Phillips Supporters for Haley (I guess???!?) 👁️]

OK, I did Iowa. The original post is updated with a link to the Iowa 2020 population estimates DRA file. If you want to try using the data, as with the Virginia data you just need to download the file and overwrite your existing file in your Iowa DRA folder.



Here is a possible map using the 2020 estimates for Iowa which does not split any counties. It is pretty similar to the map Nyvin posted, but IA-01 an IA-02 are more compact. The population deviations are -249, 1865, -1841, and 226. You may be able to get the deviations down further without splitting counties with some alternative configurations, but the deviations are clearly well within the error of the estimates.



Since Iowa likes to avoid splitting counties, very slight error between population projections and the actual 2020 census data could lead to a significantly different map. But it does seem like it may be possible to have a neat compact Des Moines area map, 2 fairly compact districts in the east, and 1 in the west.

Iowa is another state where Republicans tend to be self-packed in the western part of the state. So it is pretty much inevitable that IA-04 will in some form or other be safe R, and the other 3 districts swing districts to some extent or other, unless maybe IA-04 is re-oriented in the northern part of the state instead of the west.

IA-01 is D + 0.4
IA-02 is D + 0.8
IA-03 is D + 2.3
IA-04 is R + 13.3

[Former Dean Phillips Supporters for Haley (I guess???!?) 👁️]

Here's an alternate map for Iowa, pretty similar to the other one. The population deviations are all below 1000 on this one.



The districts look maybe slightly more compact overall, but less so the Des Moines district (IA-03) and the Des Moines IA southern suburbs/exurbs are split from IA-03.

IA-01 is D + 0.5
IA-02 is R + 0.3
IA-03 is D + 2.9
IA-04 is R + 12.9

Overall I would guess the 2020 map may look broadly similar to these two maps.

[Former Dean Phillips Supporters for Haley (I guess???!?) 👁️]

This look pretty good!   Your map pretty much confirms to me that it's near impossible to have a compact map and keep Linn and Johnson counties in the same district, lol.

This seems to be about the best that can be managed while keeping Johnson and Linn together. But it has a population deviation of a bit more than 2000 on IA-04, and Linn county is sticking out awkwardly.

[Former Dean Phillips Supporters for Haley (I guess???!?) 👁️]

Nice,  what are the PVI's for that?  It looks like the map the Republicans would push for since it creates somewhat of a Dem Pack in the southeast district.

IA-01 is D+5.0 (this is the one with Johnson and Linn, I accidentally switched IA-01 and IA-02)
IA-02 is R+1.7
IA-03 is R+0.3
IA-04 is R+13.5



Next up will be Georgia. For Georgia, I actually managed to get 2020 projections by race into the data as well as total population for Georgia, by combining the 2017 county level population estimates with race data for 2012-2016. Basically I used the 2017 data projected forward linearly to project the total population in each county in 2020, and used the ACS race/Hispanic origin data also projected forward linearly to determine the racial composition of that total growth. This methodology seems to match pretty closely with the more up to date estimates from the census for Georgia statewide. That makes it possible to actually look forward in a meaningful way to what districts might be like in the context of the VRA. This process is significantly more laborious in making the estimates though, so I don't know how many states I will do this for, but it can be done for states where race data is really needed because of the VRA.

[Former Dean Phillips Supporters for Haley (I guess???!?) 👁️]

The original post is updated with a link to the DRA file for Georgia projections for 2020. This includes projections for Race and Hispanic Origin for 2020, not just total population as previous states so far have had.



Now for some maps made with the data. If the Georgia GOP retains full control of redistricting, they will presumably draw a map similar to the current map, but probably will try to split up the Atlanta suburbs a bit more to try to dilute Democratic voters and keep all the districts such as GA-06 and GA-07 safe Republican. Although possibly, they may be forced to concede another majority minority district or two because of minority population growth and the VRA.

However, if Stacey Abrams wins the Georgia gubernatorial race, we would get something different - a court drawn map after she vetoes the Republican gerrymander.

Court Drawn Map #1 (GOP Leaning Semi-Least-Change)

Here is one hypothetical court drawn map. This map is generally similar to the pre-existing gerrymander drawn by the Georgia GOP, but districts are sucked into the Atlanta area due to population growth, and the districts are generally a bit more compact and follow county lines more. Since it generally follows the current Republican gerrymander (maybe not exactly a "least change" map, but something like it), this is probably about the best court-drawn map that the GOP could hope for. The North Atlanta suburbs districts (GA-06, GA-07, and GA-11) all have Republican PVIs, but Clinton probably won most and quite possibly all of them. So those may all be swing districts for the moment.



GA-01: R+6.9; 57.9% White, 30.7% Black, 46.1% Obama '08, 53.4% McCain '08
GA-02: D+3.7; 40.1% White, 50.1% Black, 55.5% Obama '08, 44.0% McCain '08
GA-03: R+20.2; 70.7% White, 20.6% Black, 33.3% Obama '08, 65.9% McCain '08
GA-04: D+30.9; 25.5% White, 58.8% Black, 80.3% Obama '08, 19.1% McCain '08
GA-05: D+30.1; 24.9% White, 64.0% Black, 79.4% Obama '08, 20.0% McCain '08
GA-06: R+7.0; 55.2% White, 14.2% Black, 43.1% Obama '08, 56.1% McCain '08
GA-07: R+2.2; 36.6% White, 30.3% Black, 44.6% Obama '08, 54.6% McCain '08
GA-08: R+19.7; 60.7% White, 28.0% Black, 34.4% Obama '08, 64.9% McCain '08
GA-09: R+31.4; 79.1% White, 4.4% Black, 22.2% Obama '08, 76.7% McCain '08
GA-10: R+22.1; 66.9% White, 14.3% Black, 32.3% Obama '08, 66.7% McCain '08
GA-11: R+3.9; 50.3% White, 28.1% Black, 45.1% Obama '08, 54.0% McCain '08
GA-12: R+6.5; 54.4% White, 37.2% Black, 46.4% Obama '08, 53.1% McCain '08
GA-13: D+7.4; 31.3% White, 51.8% Black, 56.4% Obama '08, 43.0% McCain '08
GA-14: R+26.9; 78.4% White, 8.6% Black, 28.1% Obama '08, 70.8% McCain '08



Court Drawn Map #2 (Dem Leaning Not Based on Current Map)

Next, here is another hypothetical court-drawn map. This one does NOT follow the current GOP gerrymander as a starting point, although it does keep GA-02 the same (presuming it will probably stay about the same regardless because of the VRA).

Whereas the previous map is what Republicans might hope for from a court drawn map, this is more like what Democrats could hope for from a court drawn map. GA-12 is redrawn to combine Savannah and Augusta, which makes it a narrowly majority-minory (but plurality white) district more similar to the old GA-12. Atlanta is partially unpacked, but DeKalb County (which has almost perfect population for a district) remains packed. As with the other court-drawn map, GA-06, GA-07, and GA-11 all have somewhat Republican PVIs, but Clinton probably won them and they are winnable for Democrats. In addition to that, however, GA-10 also becomes fairly competitive, combining Athens with parts of the Atlanta suburbs.



GA-01: R+18.8; 62.5% White, 25.8% Black, 35.4% Obama '08, 64.0% McCain '08
GA-02: D+3.7; 40.1% White, 50.1% Black, 55.5% Obama '08, 44.0% McCain '08
GA-03: R+19.2; 69.7% White, 20.7% Black, 34.1% Obama '08, 64.9% McCain '08
GA-04: D+4.8; 29.1% White, 53.3% Black, 78.9% Obama '08, 20.5% McCain '08
GA-05: D+29.2; 41.9% White, 47.2% Black, 54% Obama '08, 45.4% McCain '08
GA-06: D+6.9; 52.4% White, 27.4% Black, 59.2% Obama '08, 40.1% McCain '08
GA-07: R+4.2; 35.9% White, 23.9% Black, 42.9% Obama '08, 56.2% McCain '08
GA-08: R+15.6; 60.7% White, 29.9% Black, 37.6% Obama '08, 61.7% McCain '08
GA-09: R+29.8; 71.5% White, 5.8% Black, 22.7% Obama '08, 76.4% McCain '08
GA-10: R+3.7; 50.5% White, 35.2% Black, 46.3% Obama '08, 52.9% McCain '08
GA-11: R+3.9; 50.5% White, 27.9% Black, 45.0% Obama '08, 54.1% McCain '08
GA-12: D+2.5; 49.6% White, 40.3% Black, 54.6% Obama '08, 44.9% McCain '08
GA-13: D+4.6; 37.2% White, 48.5% Black, 55.2% Obama '08, 44.2% McCain '08
GA-14: R+31.3; 79.8% White, 5.5% Black, 25.1% Obama '08, 73.8% McCain '08



9-5 Democratic Gerrymander Map

Finally, here is a Democratic gerrymander. No, this is not going to happen (there is no way Georgia Democrats will win control of the state legislature in 2018), but it is interesting to see as a what-if.

It seems possible in a Democratic gerrymander to make 9 safely Democratic seats to 5 Republican vote sinks. As compared to the court drawn maps, the Democratic votes in Atlanta are used more efficiently to make 7 Democratic seats, while GA-02 and GA-12 are strengthened and made more safe D.



Interestingly, all the Democratic and Republican districts are in contiguous blobs with the single exception of GA-12:





GA-01: R+21.2; 66.4% White, 21.5% Black, 32.4% Obama '08, 67.0% McCain '08
GA-02: D+6.7; 37.5% White, 53.7% Black, 59.3% Obama '08, 40.2% McCain '08
GA-03: R+28.9; 81.0% White, 7.0% Black, 26.6% Obama '08, 72.3% McCain '08
GA-04: D+7.7; 41.2% White, 50.3% Black, 58.9% Obama '08, 40.5% McCain '08
GA-05: D+7.6; 37.6% White, 50.8% Black, 56.4% Obama '08, 43.0% McCain '08
GA-06: D+6.3; 55.8% White, 19.6% Black, 58.2% Obama '08, 41.0% McCain '08
GA-07: D+6.2; 30.9% White, 26.9% Black, 54.8% Obama '08, 44.3% McCain '08
GA-08: R+19.1; 63.1% White, 26.0% Black, 33.8% Obama '08, 65.6% McCain '08
GA-09: R+24.4; 72.7% White, 9.6% Black, 27.4% Obama '08, 71.7% McCain '08
GA-10: D+6.1; 40.7% White, 38.3% Black, 55.2% Obama '08, 44.0% McCain '08
GA-11: D+6.4; 41.5% White, 37.6% Black, 55.4% Obama '08, 43.8% McCain '08
GA-12: D+6.7; 45.8% White, 45.2% Black, 58.5% Obama '08, 41.0% McCain '08
GA-13: D+7.5; 35.8% White, 49.3% Black, 57.9% Obama '08, 41.5% McCain '08
GA-14: R+33.9; 82.0% White, 5.1% Black, 21.5% Obama '08, 77.4% McCain '08

GA-09's shape is probably unnecessary - I only drew it that way in the vague hope that maybe if the North Atlanta suburbs keep trending D, it could some day (maybe in 2028 or 2030) becomes somewhat competitive. I doubt that would really happen, but it would be interesting to see the Clinton-Trump numbers in this district to judge if that is at all within the realm of possibility.

[Former Dean Phillips Supporters for Haley (I guess???!?) 👁️]

IA is made difficult because it is so thoroughly driven by the cold calculus of geography and population. In states that have humans chop counties to exact equality it is far more likely that we might get close if we can get inside the heads of those who will draw the map.

Agreed. A small amount of error can make a big difference in Iowa. Not only are there changes in each year's population estimates, but there are also always some surprises when the actual census data comes out, in comparison to the estimates.

[Former Dean Phillips Supporters for Haley (I guess???!?) 👁️]

Dallas County, Iowa has had some major population growth.

Of course it has. Dallas county has been averaging 3.9% growth per year so far this decade. That's why I don't use the current estimate, I forecast a projection to 2020 based on that rate of growth. For example the 7/1/17 estimate is 87,235 but I use a 2020 population of 96,896.

The question here is whether the rate of population growth in Dallas county will be faster or slower over the next 3 years than it has been over the previous 7. Are you suggesting that the growth rate will be significantly higher in the last years of this decade than it currently is?

The methodology that I used to make my estimates is slightly different than what you used. This makes only a small difference, but it does make some difference - for example, the number I have in my DRA files for Dallas County IA is 96,278 instead of 96,896. Your method will estimate slightly higher population gains (or losses) than mine.

In the case of Iowa, that small difference of 618 people is enough to change the map, if they are trying to limit population deviations below e.g. 100 people.

What I did was to apply the growth rate for each additional year to the 2010 base estimate. What it sounds like you did was to apply the growth rate for 2018 to the 2017 base population estimate, the growth rate for 2019 to the 2018 base population estimate, etc.

I am not sure which is better; your method is more strictly mathematically adhering to a constant growth rate, in the sense in which a constant growth rate is used for calculating things like interest payments, whereas my method only has a constant growth rate with reference to a constant base population (the 2010 estimates). This means that my method adds an equal number of people each year, whereas your method adds more people each year (assuming positive growth).

The best case to be made for my method is that there is an overall downward trend in population growth rates in general across the country. I don't know this for sure, but it seems to me that when urban/suburban counties are growing, they don't very often (at least in the current stage of development) start off by adding a smaller number of people and then a larger number of people (although that could be the case for some rural counties that are becoming exurban).

The larger a county gets, the more its growth rate tends to slow down, for various reasons. First of all, population growth is declining in general across the US and across the world. Second, in the case of large metro areas, after growth has gone on for a while, there tends to be less land available in an urbanizing county, and growth moves a bit more to other counties, which then become suburban/exurban counties.

In truth, I would guess your method may be accurate for some counties/states, and mine for others. I would guess mine is probably better for most large urban counties, whereas yours may be better for counties that are in the early stages of suburbanization/urbanization.

The wild card is population loss - your method implies that if a county is losing population, it will lose a greater absolute # of people per year. That in turn implies, at least if one considers no in-migration, that a greater percentage of the existing population must be dying or moving away every year. But who knows, that could actually be the more accurate way to model some places like Detroit and to a lesser extent Cleveland.

[Former Dean Phillips Supporters for Haley (I guess???!?) 👁️]

In a county of declining population, the losses would diminish each year with my method. For example, consider a county with a 10%/year loss rate that starts with 1000 people. In the first year it would lose 100 people bringing it to 900. In the next year it would lose 90 people bringing it to 810. In the third year it would lose 81, and so on. The absolute number lost decreases each year.

Got it. Then your method is probably better for population loss to be sure. With Georgia, one problem that I had is that for some racial subgroups (mainly Native Americans and Asian, and Other) was that in some cases, I was getting negative numbers. This could happen in counties where there was a very small population and then the population projections had it declining significantly. This happened mainly given the inaccuracy/high margin of error for estimates of population loss/growth for very small populations. In those cases I simply set the population for that particular racial subgroup to a minimum of 0. But your method would, I think prevent that from happening, so I may try that for a future state, in particular if I try to make race data projections again.

[Former Dean Phillips Supporters for Haley (I guess???!?) 👁️]

In a county of declining population, the losses would diminish each year with my method. For example, consider a county with a 10%/year loss rate that starts with 1000 people. In the first year it would lose 100 people bringing it to 900. In the next year it would lose 90 people bringing it to 810. In the third year it would lose 81, and so on. The absolute number lost decreases each year.

Got it. Then your method is probably better for population loss to be sure. With Georgia, one problem that I had is that for some racial subgroups (mainly Native Americans and Asian, and Other) was that in some cases, I was getting negative numbers. This could happen in counties where there was a very small population and then the population projections had it declining significantly. This happened mainly given the inaccuracy/high margin of error for estimates of population loss/growth for very small populations. In those cases I simply set the population for that particular racial subgroup to a minimum of 0. But your method would, I think prevent that from happening, so I may try that for a future state, in particular if I try to make race data projections again.

Since the Census Bureau produces racial estimate, why not use those directly?

I am using the census race estimates as the basis for projections, but I am not quite sure what you mean by using them "directly." My guess is that maybe you mean something like "why not just take the most recent race estimates from the American Community Survey and project them forward to 2020?"

If so, the reason for not doing that is that I was worried about the higher sampling error of race data as opposed to total population estimates. The other issue is that the American Community Survey data comes either as 5 year average estimates, 3 year estimates, or 1 year estimates, with the more recent estimates reflecting more recent population changes, but having higher error because they are based on fewer survey responses.

So my presumption was that the total population estimates for each county would generally have less measurement error. And secondly, my presumption was that it would probably reduce overall error by more if I used 5 year average (2012-2016) ACS data, to reduce the variance of race data, particularly for small counties, as opposed to using the most recent ACS 1-year race estimates in combination with the most recent ACS total population estimates. I would think this is especially important for getting somewhat accurate reads on the smaller racial groups (Asians, Native American, Other, etc), because in some years there may be literally 0 people who participate in the ACS in certain counties. I think I even remember from a few years ago seeing some cases where ACS doesn't provide estimates at all for certain geographies if the population is too small.

Of course, that could be wrong (and surely is, in at least some cases). In particular in very large counties (for example, Los Angeles County, CA), if there is a sufficient sample size in the 1 year ACS estimates, it would probably be more accurate to use the most recent 1 year estimates rather than jerry-rigging 2012-2016 race estimates onto 2017 total population estimates.

[Former Dean Phillips Supporters for Haley (I guess???!?) 👁️]

Alright, next up is Texas. It turns out that the Texas state government has its own population projections for 2020, which include race data by county. Although these estimates were apparently made in 2014, so they may not quite include the very latest changes in population trends, it saves a lot of work to just use those. And if they are good enough for the Texas state government to use in their own planning, they are good enough for my purposes.

https://www.dshs.texas.gov/chs/popdat/st2020.shtm


The only thing previously holding back Republican gerrymanders of Texas from being more lopsided than the current map is was the Voting Rights Act. However, with the retirement of Kennedy and Kennedy's failure to do anything about partisan gerrymandering, it is my presumption that the Supreme Court with Trump's new nominee will allow Texas to basically ignore the VRA (and perhaps even declare that its application to redistricting is unconstitutional) and redistrict for partisan purposes however they want. Moreover, Texas Republicans have not been known for restraining themselves in redistricting.

Therefore I would not expect the voting rights act to stand as a limit on Republican gerrymandering any longer. The result of this is likely to be a highly effective and partisan map similar to the current North Carolina and Ohio maps, which entirely disregards all other considerations besides the partisan rigging Congressional of elections.

There is no prospect I can see of either a court drawn map/neutral map or a Democratic gerrymander. So I drew a Republican gerrymander using this 2020 data, presuming that Texas gains 2 Congressional districts (so TX will have 38 districts). The map is a 35-3 Republican map, in which all 35 Republican districts are extremely safe (about R+11.5 each). The purpose of this map is to institute apartheid in Texas:









TX-1 (R+11.0): 40.2% White, 8.1% Black, 41.1% Hispanic, 37.3% Obama '08, 62.7% McCain '08
TX-2 (R+11.1): 48.7% White, 21.2% Black, 23.9% Hispanic, 43.4% Obama '08, 56.6% McCain '08
TX-3 (R+11.8 ): 51.3% White, 11.1% Black, 19% Hispanic, 39.1% Obama '08, 60.9% McCain '08
TX-4 (R+11.8 ): 44.1% White, 15.8% Black, 35.1% Hispanic, 40.6% Obama '08, 59.4% McCain '08
TX-5 (R+11.7): 47.7% White, 7.9% Black, 33.5% Hispanic, 39.6% Obama '08, 60.4% McCain '08
TX-6 (R+11.7): 48.4% White, 15.5% Black, 27.3% Hispanic, 41.1% Obama '08, 58.9% McCain '08
TX-7 (R+11.2): 35.8% White, 17.2% Black, 31.4% Hispanic, 40% Obama '08, 60% McCain '08
TX-8 (R+11.9): 48.4% White, 12% Black, 26.6% Hispanic, 38.8% Obama '08, 61.2% McCain '08
TX-9 (R+11.1): 44.3% White, 12.8% Black, 30.7% Hispanic, 40% Obama '08, 60% McCain '08
TX-10 (R+11.7): 40.9% White, 3.1% Black, 50.8% Hispanic, 41.7% Obama '08, 58.3% McCain '08
TX-11 (R+11.1): 33.8% White, 11.9% Black, 41.7% Hispanic, 38.6% Obama '08, 61.4% McCain '08
TX-12 (R+11.7): 40.1% White, 13.5% Black, 41.5% Hispanic, 40.4% Obama '08, 59.6% McCain '08
TX-13 (R+11.5): 25.9% White, 3.7% Black, 68.1% Hispanic, 38.4% Obama '08, 61.6% McCain '08
TX-14 (R+11.4): 33.2% White, 4.3% Black, 59.1% Hispanic, 41.7% Obama '08, 58.3% McCain '08
TX-15 (R+11.3): 31.9% White, 4.6% Black, 59.9% Hispanic, 41.7% Obama '08, 58.3% McCain '08
TX-16 (R+11.4): 33.1% White, 3.5% Black, 60.3% Hispanic, 40.8% Obama '08, 59.2% McCain '08
TX-17 (R+11.6): 63.8% White, 3.4% Black, 25.1% Hispanic, 41.4% Obama '08, 58.6% McCain '08
TX-18 (D+36.9): 8.6% White, 50.4% Black, 35.6% Hispanic, 88.5% Obama '08, 11.5% McCain '08
TX-19 (R+11.5): 32.8% White, 4.2% Black, 58.7% Hispanic, 39.3% Obama '08, 60.7% McCain '08
TX-20 (R+11.4): 36.9% White, 4.4% Black, 54.5% Hispanic, 41.1% Obama '08, 58.9% McCain '08
TX-21 (R+11.6): 51.5% White, 12.2% Black, 27% Hispanic, 42.4% Obama '08, 57.6% McCain '08
TX-22 (R+11.0): 39.3% White, 13.9% Black, 26% Hispanic, 38.7% Obama '08, 61.3% McCain '08
TX-23 (R+11.6): 39.7% White, 9.3% Black, 47.2% Hispanic, 42.3% Obama '08, 57.7% McCain '08
TX-24 (R+11.9): 46.1% White, 11% Black, 29.6% Hispanic, 39% Obama '08, 61% McCain '08
TX-25 (R+11.6): 44.4% White, 14.6% Black, 36.4% Hispanic, 42% Obama '08, 58% McCain '08
TX-26 (R+11.7): 46.5% White, 9.5% Black, 37.2% Hispanic, 41.3% Obama '08, 58.7% McCain '08
TX-27 (R+11.5): 34.1% White, 5.8% Black, 55.9% Hispanic, 41.2% Obama '08, 58.8% McCain '08
TX-28 (R+11.5): 32.5% White, 3.4% Black, 61.9% Hispanic, 40.7% Obama '08, 59.3% McCain '08
TX-29 (R+11.0): 30.8% White, 7.9% Black, 57.6% Hispanic, 39.4% Obama '08, 60.6% McCain '08
TX-30 (D+34.5): 9.9% White, 49.2% Black, 37.3% Hispanic, 85.1% Obama '08, 14.9% McCain '08
TX-31 (R+11.5): 50% White, 4.2% Black, 40.2% Hispanic, 40.3% Obama '08, 59.7% McCain '08
TX-32 (R+11.7): 48% White, 11.7% Black, 34.9% Hispanic, 42.3% Obama '08, 57.7% McCain '08
TX-33 (R+11.6): 44.6% White, 9.4% Black, 34.9% Hispanic, 40.1% Obama '08, 59.9% McCain '08
TX-34 (R+11.5): 30.4% White, 0.8% Black, 66.6% Hispanic, 42% Obama '08, 58% McCain '08
TX-35 (D+25.2): 41.1% White, 8.4% Black, 41.6% Hispanic, 74% Obama '08, 26% McCain '08
TX-36 (R+11.1): 37.2% White, 16.4% Black, 42.9% Hispanic, 41.1% Obama '08, 58.9% McCain '08
TX-37 (R+11.1): 34.5% White, 13.1% Black, 48.2% Hispanic, 39% Obama '08, 61% McCain '08
TX-38 (R+11.5): 31.9% White, 2% Black, 64% Hispanic, 39.4% Obama '08, 60.6% McCain '08

There is only one single Democratic district in Houston, only one single Democratic district in Dallas, and only one single Democratic district in Austin. Because Hispanic voter turnout is so low, it is more efficient in nakedly partisan terms to cede a safe D seat in Austin than one in San Antonio or the McAllen area. San Antonio, El Paso, and the rest of the Hispanic areas along the border are all cracked between multiple ~R+11.5 safe Republican districts.

The result of this is that the 2 Dallas/Houston seats will be dominated by Black Democratic voters, and the Austin seat will end up being dominated by White Democratic voters (although there is a substantial Hispanic population in Austin, turnout remains low). All the other 35 seats will be dominated by White Republican voters. No seats whatsoever will be dominated by Hispanic voters (despite the fact that Hispanics make up a plurality of the Texas population in these 2020 estimates).

I won't make any particular effort to distinguish which district is which, since it doesn't really matter - all the R districts are basically the same, about R+11.5, give or take. The lines are more erose than they really need to be for 2 reasons -

1) Because I tried to give all Republican districts roughly the same partisanship. If you are willing to accept some districts that are "only" R+10, R+9, etc, then you can make the lines more compact looking.

2) Because I tried to give all (or at least almost all) of the Republican districts some heavily R rural areas, not just suburbs. That way, if the suburbs swing D, the rural areas probably won't, and that helps keep the district safe R.



Is this a dummymander? I think you would be hard pressed to argue that it is. Even if Texas trends Democratic, all of these districts are significantly more Republican than Texas as a whole. The 3 Democratic pack districts are very "efficient" at removing any realistic prospect of any of the other districts ever having a remotely competitive election. Furthermore, if any districts do become remotely competitive, Texas Republicans can always redistrict mid-decade to make whatever adjustments are necessary to rig the elections in their favor. You could add another Dem pack district or two in San Antonio, El Paso, or McAllen-Brownsville, but this only has the effect or increasing the R+ of the other districts by about 1 point per additional vote sink because Hispanic turnout is so low. Why bother conceding low-turnout Hispanic vote sinks when you can just mid-decade redistrict if you feel the need to concede an additional vote sink?

Moreover, even in the seemingly unlikely event that the Supreme Court rules against a hyper-aggressive TX Republican gerrymander, the litigation process is likely to take several election cycles worth of time before it finally gets to SCOTUS, during which time the GOP will have successfully rigged the elections and sabotaged American democracy for probably at least half a decade.



My further conclusion (from a Dem perspective) based on this map is that if Democrats want to have any hope of controlling Congress in the 2020s, they had better hurry up and abolish California's Independent Redistricting Commission and pass a 53-0 Democratic Gerrymander there in order to offset the TX GOP gerrymander and other gerrymanders. This way, although the electoral system will still be rigged, it will at least be rigged symmetrically.

[Former Dean Phillips Supporters for Haley (I guess???!?) 👁️]

I am cross-posting this in this old thread, adding a link to the 2016 Clinton precinct estimates file for Dave's Redistricting App.

I am thinking of also doing the same thing of estimating 2016 or 2018 precinct data for some other states potentially (maybe Beto-Cruz TX-Sen and Abrams-Kemp GA-GOV precinct results estimates for TX and GA in particular, and maybe Clinton-Trump precinct estimates for NY).

Here a rudimentary 2020 map showing that you can still get two Blue seats out of downstate - as you can see I'm still working on Chicagoland. Both seats are between D+4 and D+5 PVI, and they can get more democratic. I wanted to keep my tentacles 'thick' and actually logical, but this adds pubs. If you connect the cites using thin bacon strips, you can hit D+5 or more.

A lot I feel depends on 2020 regarding Illinois. How democratic the collar counties get/stay/remain and whether IL-14 remains in dem hands determines if the seat needs to go Pub to shore up everyone else.

I made a 14-3 Illinois map a while back, but that was under the assumption of Hultgren holding on and mashing him up with Kinzinger. There were two snake-like downstate Democratic districts and 12 Chicagoland Hillary seats. All met VRA requirements and all were at least 55% Hillary (the 12 Chicagoland seats were all at least 58% Hillary). Could probably baconstrip out Chicagoland a little more for Lauren Underwood and try to get a 15-2.

It is very easy to draw a 14-3 for IL. The Democratic Party of Illinois should just go ahead and disband if they can't even manage to draw a 14-3 while Rs draw egregious maps in other states.

IL is a state where PVI including 2012 results is not really as informative as you would like. I don't think the suburban/rural trends are going away, and I think it sort of makes more sense to draw districts based on the 2016 vote more than PVI (many states are like this to some degree, but IL probably in particular).

I started trying to draw an IL map with 2016 PVI data, but it was too cumbersome and annoying to not have the Clinton-Trump numbers. So I made 2016 precinct result estimates for IL and used those instead as my basis for drawing districts. Since the only precinct results data directly accessible in the DRA files is unfortunately the 2008 results (PVI does not show up in the files that download to your computer, despite the fact that they obviously have it), so the 2016 estimates are made using 3 assumptions:

1) The distribution of turnout across precincts within each county was constant from 2008 to 2016 (basically, turnout increased by the same % in each precinct within the same county, but precincts within different counties went up by a different % than each other).
2) That within each county, each voter regardless of precinct had the same individual probability of switching from Obama to Trump, Obama to 3rd Party, or McCain to Clinton.

Estimating the precinct results is not as good as having the actual precinct results, obviously, but I think it is better than just having PVI. You can see there is a lot more deep red in rural downstate IL (which makes it easier to vote sink the Rs) and a lot more blue in suburban Chicagoland (which makes it much easier to draw Dem districts there). The numbers still display in the DRA interface as "President 2008," but you can see that the actual #s of votes match the 2016 results (Clinton getting 3.09 million votes and Trump getting 2.15 million, but the interface still displays them as "Oba" and "McC"):



I uploaded the estimates here in case anyone else wants to try using them here:

http://s000.tinyupload.com/index.php?file_id=31184931103049287168



It is very annoying how they put the PVI data in to Dave's Redistricting App, because first of all you can't see it visually on the map, and secondly because it doesn't show the actual underlying data. You know that they have to have both the 2012 and 2016 precinct results in order to calculate PVI, but you can't see the results separately.

For districts where there is a large trend (like in both rural and suburban IL), if you are trying to draw a map that will be resistant against a continuation of the trend, it is much more helpful if you can separately see the Obama-Romney and Clinton-Trump numbers than if you can only see them mashed together into PVI.

Using 2016 results actually seems to make IL much easier to gerrymander than it was in 2010 or than it was with even 2016 PVI, because with 2016 data, polarization is stronger and Rs can be more easily packed into rural vote sinks. In general higher polarization makes it easier to gerrymander effectively, whereas it is harder if every precinct is 55-45.



Anyway, so here is a 14-3 map, which has 2 downstate Dem districts drawn in the obvious way and 12 Chicagoland districts. All Democratic incumbents should live in their districts (or else very nearby, so that they could be easily drawn in), and I tried to preserve as much of their current territory as reasonably possible.









Here are the stats for the districts. This includes the (estimated) Clinton 2016 vote, the PVI that averages 2016 and 2012, and as normal, and . I drew the districts basically entirely on the basis of the estimated Clinton vote. Since the 2016 data is just an estimate and is based on the geographical distribution of Dem votes within each county from 2008, the relationship between the estimated Clinton vote and PVI is not exact. In general it should be possible to draw districts with a similar Clinton vote as in this map, but the PVIs may be a bit different and the actual precincts include may differ a bit because of the fact that Dems have in reality gained more or lost more in certain areas within each county than others. I basically kept the inner Chicago area districts about the same as they are now, although if it were me making the map in reality I would probably want to add a second Hispanic district. But the 2020 population estimates (I am using the ones cvparty made) seem to underestimate the Hispanic population a bit as compared to current #s. If the Clinton vote on any of the suburban Chicago districts is not considered safe enough, it is pretty easy to gerrymander more because there are plenty of extra votes in Chicago, particularly in IL-05 and IL-09.

IL-01: Clinton 71.1% - Trump 24.1%, (D+21.7) [[Obama 77.4% - McCain 21.9%]], Majority African American
IL-02: Clinton 72.3% - Trump 23.1%, (D+24.4) [[Obama 77.3% - McCain 21.9%]], Majority African American
IL-03: Clinton 57.8% - Trump 38.4%, (D+4.6) [[Obama 57.4% - McCain 41.4%]]
IL-04: Clinton 79.6% - Trump 15.6%, (D+34.0) [[Obama 81.8% - McCain 16.9%]], Supermajority Hispanic
IL-05: Clinton 69.1% - Trump 26.1%, (D+19.6) [[Obama 70.1% - McCain 28.6%]]
IL-06: Clinton 55.1% - Trump 39.3%, (D+3.8 ) [[Obama 55.5% - McCain 43.2%]]
IL-07: Clinton 84.7% - Trump 10.8%, (D+36.1) [[Obama 87.5.5% - McCain 11.7%]], Majority African American
IL-08: Clinton 55.0% - Trump 39.8%, (D+3.1) [[Obama 57.5% - McCain 41.2%]]
IL-09: Clinton 64.6% - Trump 31.5%, (D+13.9) [[Obama 64.6% - McCain 34.2%]]
IL-10: Clinton 55.2% - Trump 38.8%, (D+4.5) [[Obama 58.8% - McCain 40.0%]]
IL-11: Clinton 54.7% - Trump 39.4%, (D+6.2) [[Obama 59.1% - McCain 39.8%]]
IL-12: Clinton 28.4% - Trump 67.2%, (R+17.6) [[Obama 44.8% - McCain 53.4%]]
IL-13: Clinton 50.3% - Trump 43.4%, (D+5.2) [[Obama 61.5% - McCain 36.9%]]
IL-14: Clinton 52.9% - Trump 40.8%, (D+3.8 ) [[Obama 58.3% - McCain 40.3%]]
IL-15: Clinton 27.0% - Trump 68.1%, (R+20.0) [[Obama 42.7% - McCain 55.6%]]
IL-16: Clinton 36.0% - Trump 58.1%, (R+11.0) [[Obama 47.4% - McCain 50.9%]]
IL-17: Clinton 49.5% - Trump 43.8%, (D+4.4) [[Obama 59.7% - McCain 38.7%]]



So I think this shows it is pretty easy to draw a 14-3 map. However, I think this most obvious way is probably not the *best* way to do so. Mainly this is because IL-13 and IL-17 both only voted for Clinton by about 6-7 points, and are vulnerable to potentially trending further Republican if Republicans continue to gain among white voters outside of major urban/suburban areas.

So, here is an alternative that tries to avoid that being a problem.

IL-13 is made significantly more Democratic by giving it the pick of Democratic precincts in Bloomington and Carbondale, in addition to East St. Louis, Springfield, Decatur, and Champaign which it already had in the previous map.

And IL-17 is sured up by drawing it into Chicagoland - specifically by dropping Peoria and Bloomington and instead drawing it in to Waukegan. Why Waukegan specifically? First, it is a pretty easy straight shot along the IL border from Rockford. And secondly, Waukegan is filled with lots and lots of non-whites. With the 2020 estimates from cvparty (I think they may be underestimates on the racial #s), that drops IL-17 all the way from to only 68% white, compared to the current real life IL-17 which is 83% white. So that makes Cheri Bustos far far less vulnerable to potential further GOP gains among white voters. Alternatively, you could maybe draw IL-17 into other areas with Dem voters like De Kalb, Elgin, or Auraura to achieve a similar effect. But I wanted to keep most of those for IL-14.

Since IL-17 no longer has Peoria, that leaves it up for grabs. Who gets it? In this case, IL-14. Springfield does actually have a decently sized African American population, and the way IL-14 is drawn in this map brings it down to 60% White and up to 9% African American. Since the real life current version of IL-14 is 86% White and only 3% African American, and since Lauren Underwood is African American, although she is clearly able to win over white voters, she probably won't complain too much about being given Peoria and bumping up the African American population a tad. Another way to look at it is that it gives her some downstate exposure to set her up for a statewide run later on if she wants to give that a try at some point.










IL-01: Clinton 71.1% - Trump 24.1%, (D+21.7) [[Obama 77.1% - McCain 22.1%]], Majority African American
IL-02: Clinton 72.3% - Trump 23.1%, (D+24.4) [[Obama 77.7% - McCain 21.4%]], Majority African American
IL-03: Clinton 57.8% - Trump 38.4%, (D+4.6 ) [[Obama 57.4% - McCain 41.4%]]
IL-04: Clinton 79.6% - Trump 15.6%, (D+34.0) [[Obama 81.8% - McCain 16.9%]], Supermajority Hispanic
IL-05: Clinton 69.1% - Trump 26.1%, (D+19.6 ) [[Obama 70.1% - McCain 28.6%]]
IL-06: Clinton 55.1% - Trump 39.3%, (D+3.8) [[Obama 55.5% - McCain 43.2%]]
IL-07: Clinton 84.7% - Trump 10.8%, (D+36.1) [[Obama 87.5.5% - McCain 11.7%]], Majority African American
IL-08: Clinton 54.2% - Trump 40.9%, (D+2.7) [[Obama 56.7% - McCain 41.9%]]
IL-09: Clinton 63.3% - Trump 32.7%, (D+12.4) [[Obama 63.4% - McCain 35.5%]]
IL-10: Clinton 54.0% - Trump 40.2%, (D+3.5) [[Obama 57.9% - McCain 40.9%]]
IL-11: Clinton 53.7% - Trump 40.4%, (D+5.0) [[Obama 58.2% - McCain 40.6%]]
IL-12: Clinton 29.0% - Trump 66.5%, (R+17.1) [[Obama 44.9% - McCain 53.3%]]
IL-13: Clinton 53.1% - Trump 40.0%, (D+7.8) [[Obama 63.5% - McCain 34.8%]]
IL-14: Clinton 53.5% - Trump 39.8%, (D+5.8) [[Obama 60.2% - McCain 38.3%]]
IL-15: Clinton 29.0% - Trump 65.8%, (R+19.0) [[Obama 42.3% - McCain 56.0%]]
IL-16: Clinton 32.8% - Trump 61.5%, (R+12.6) [[Obama 47.3% - McCain 51.0%]]
IL-17: Clinton 51.7% - Trump 42.1%, (D+4.9) [[Obama 60.7% - McCain 37.8%]]


If any of the Chicagoland districts are not considered to be safe enough, it is pretty easy to make them all safer by giving IL-09 some more of Lake County, etc. But as long as Dems continue to do well with suburban voters in Chicagoland, and the trend in the Trump era is not reversed, these districts should all be pretty safely Dem for the foreseeable future.



So, since 14-3 is clearly quite easy to do, what about 15-2? For that, it seems like you have to baconmander quite a bit more. I haven't played around with it enough to figure out the best way of doing it, but it is definitely possible. It is (probably) ugly though. Here is a partial attempt I made at 15-2 (which also adds a 2nd Hispanic district and draws Lipinski out to Peoria), but I gave up on it since it was both clear that it was possible to get to 15-2 but also clear that it would be ugly. But maybe someone can come up with a cleaner looking way of doing it. I also had to use touch point contiguity to have IL-15 cross through the tentacle of IL-12 that connects East St. Louis and Springfield: