Dave's Redistricting App

[Bo]

Here's Maryland with 3 black-majority districts and 4 McCain districts.



CD-1 (Blue): 52-46 McCain
CD-2 (Green): 64% Black, 87% Obama
CD-3 (Purple): 57-41 McCain
CD-4 (Red): 54% White, 73% Obama
CD-5 (Yellow): 51-47 McCain
CD-6 (Teal): 55% Black, 80% Obama
CD-7 (Gray): 54-44 McCain
CD-8 (Light Purple): Just over 50% Black, 83% Obama

I should probably play around with the border between Districts 6 and 8 to increase District 8's black percentage.

Note: District numbers were selected for good color contrast with the partisan data layer enabled, and are not intended to reflect real life district numbers.

I think the Justice Department might block this map because CD-2 crams much more black voters than is necessary.

Yet the plan still manages one more black-majority district than the current map.

Still, I am aware that improvements can be made, and you've inspired me to add to CD-8's black population by taking black voters from CD-2 instead of CD-6. Here is the result:



CD-1 (Blue): Unchanged. See above.
CD-2 (Green): 57% Black, 83% Obama
CD-3 (Purple): 52-47 McCain
CD-4 (Red): Unchanged. See above.
CD-5 (Yellow): 54-44 McCain
CD-6 (Teal): Unchanged. See above.
CD-7 (Gray): Unchanged. See above.
CD-8 (Light Purple): 52% Black, 83% Obama

This plan manages to increase the black population in the least black black-majority district as well as widen McCain's margin in the district he performed worst in of the ones he carried. Overall, I consider this an improvement.

Here's a zoomed in view of the beltway.

Your revised map seems pretty legit. That's probably what the GOP will do if they completely gain control of the state govt. before redistricting. Not that this is likely to happen anytime soon, though.

[Bacon King]

Neat! Here's the four McCain district MD I did a while back

And now here's a GOP gerrymander of Maryland! Under good conditions, anyway.



Blue: McCain+8
Green: McCain+11
Grayish Blue: McCain+7
Teal: McCain+8
Purple: Obama+79
Red: Obama+43
Yellow: Obama+48
Gray: Obama+79

[Bo]

Neat! Here's the four McCain district MD I did a while back

And now here's a GOP gerrymander of Maryland! Under good conditions, anyway.



Blue: McCain+8
Green: McCain+11
Grayish Blue: McCain+7
Teal: McCain+8
Purple: Obama+79
Red: Obama+43
Yellow: Obama+48
Gray: Obama+79

What are the racial/ethnic demographics of each district?

[Bacon King]

Lol, I don't know, but I'm assuming gray and purple are pretty strongly majority black.

[Dgov]

A Democratic gerrymander of Georgia! Partially inspired by the 2000-2004 map.



1st (deep blue): Safe GOP. [72% white, 21% black]
2nd (dark green): Safe DEM. [47% white, 46% black]
3rd (purple): Safe GOP. [79% white, 15% black]
4th (red): Safe/Strong lean DEM. [41% black, 41% white, 12% hispanic]
5th (yellow): Safe/strong lean DEM. [46% white, 40% black]
6th (teal): Safe GOP. [79% white]
7th (gray): lean DEM. [44% white, 24% hispanic, 21% black]
8th (bluish one in the middle): Strong lean DEM [55% white, 39% black]
9th (light blue in the north): Safe GOP [88% white]
10th (pink): Safe GOP [79% white, 12% black]
11th (light green): lean DEM. [48% white, 32% black, 16% hispanic]
12th (the eastern bluish one): Strong lean DEM [50% white, 42% black]
13th (peach/salmon): Safe DEM [51% black, 37% white]
14th (brown): Strong lean DEM [49% white, 43% black]

nine out of fourteen districts democratic!

Uh, the 11th, 7th, 8th, and 12th in that map would all Lean Republican.

7th:  Hall county Hispanics are either Strongly Republican or don't vote at all, given as that county voted 75% Republican, and Western Gwinnet county is swing territory at best for the Democrats.

8th:  The Southeastern portion of  this district is staunchly Republican, enough to more than offset any Democratic lean in the Macon part of the district.

11th: Any district based in Cobb county suburbs is going to be unwinnable for the Democrats, even more so with those tendres extending up into overwhelmingly Republican NW Georgia.

12th:  A Republican won a district with almost that exact shape a few years ago, so it's certainly not a safe district for the democrats by any stretch of the imagination.

[muon2]

Since we are talking about MD, I thought I would add my version from last year.

I had put together a map of MD a couple of years ago based on 2010 projections. I adapted it to the 2008 data on the App to get the following map.



The districts are all within 100 persons of the ideal number, and were designed to minimize the number of split counties. There are Two majority Black districts. Using the voting data on the App, here's how they come out with the percentage of the two-party 2008 presidential vote:

CD-1 (blue) R+16
CD-2 (green) R+9
CD-3 (purple) R+3
CD-4 (red) D+41
CD-5 (yellow, 67% Black) D+73
CD-6 (teal) D+2
CD-7 (gray, 63% Black) D+76
CD-8 (lavender) D+48

[Dgov]

Just so you know, the D+XX and R +XX numbers refer to how much above the national average Presidential candidates got in that district.  So in a district that went 63% for Obama, the rating would be D + 10.

a D + 76 District would mean Obama got roughly 129% there, which sounds about right for a North Korean election, but not an American one.

[muon2]

Just so you know, the D+XX and R +XX numbers refer to how much above the national average Presidential candidates got in that district.  So in a district that went 63% for Obama, the rating would be D + 10.

a D + 76 District would mean Obama got roughly 129% there, which sounds about right for a North Korean election, but not an American one.

Your definition is specifically for the Cook PVI. That measure requires a comparison to the nation as a whole. Many districts do not swing as much, or swing more, than the nation as a whole. I like to see how a district would perform in the specific election (or composite of elections) independent of the national average.

The definition I've used is a straight competitiveness measure. My definition refers to the difference between the two party vote expressed as a percentage of the two party vote. This measure does show up in some application. For instance, last year's Ohio Redistricting Competition used the d-r% definition to measure the competitiveness of a district in their contest.

In any case one can convert between the two by shifting my numbers by the 2008 presidential winning margin of 7% then dividing by two.

[Bacon King]

A Democratic gerrymander of Georgia! Partially inspired by the 2000-2004 map.



1st (deep blue): Safe GOP. [72% white, 21% black]
2nd (dark green): Safe DEM. [47% white, 46% black]
3rd (purple): Safe GOP. [79% white, 15% black]
4th (red): Safe/Strong lean DEM. [41% black, 41% white, 12% hispanic]
5th (yellow): Safe/strong lean DEM. [46% white, 40% black]
6th (teal): Safe GOP. [79% white]
7th (gray): lean DEM. [44% white, 24% hispanic, 21% black]
8th (bluish one in the middle): Strong lean DEM [55% white, 39% black]
9th (light blue in the north): Safe GOP [88% white]
10th (pink): Safe GOP [79% white, 12% black]
11th (light green): lean DEM. [48% white, 32% black, 16% hispanic]
12th (the eastern bluish one): Strong lean DEM [50% white, 42% black]
13th (peach/salmon): Safe DEM [51% black, 37% white]
14th (brown): Strong lean DEM [49% white, 43% black]

nine out of fourteen districts democratic!

Uh, the 11th, 7th, 8th, and 12th in that map would all Lean Republican.

7th:  Hall county Hispanics are either Strongly Republican or don't vote at all, given as that county voted 75% Republican, and Western Gwinnet county is swing territory at best for the Democrats.

8th:  The Southeastern portion of  this district is staunchly Republican, enough to more than offset any Democratic lean in the Macon part of the district.

11th: Any district based in Cobb county suburbs is going to be unwinnable for the Democrats, even more so with those tendres extending up into overwhelmingly Republican NW Georgia.

12th:  A Republican won a district with almost that exact shape a few years ago, so it's certainly not a safe district for the democrats by any stretch of the imagination.

7th: Hall County voted 75% for McCain, yes, but almost all of the remotely Democratic areas of the County are in this district- including parts of Gainesville that were >90% Obama. Four of Hall's five commissioners are elected from districts, and a Democrat holds the only district contained entirely within the 7th district on this map. A better gerrymander would have been "stringier", and cut more of the rural white southern portion of the county, but I don't think that's really necessary here. And regarding the Gwinnett, portion of the district, it's better territory for Democrats than you think. Gwinnett only voted 54.5% McCain, and the most Republican parts of the county are in the eastern half. Note that four of the eight Gwinnett State Representative districts in the 7th here are Democratic; there's only one other Democratic State Rep in the county. This isn't a district that a Democrat would have a guaranteed win in, no, but once won was elected the incumbency would be enough to keep him/her in.

8th: Marshall wouldn't have any problem holding this district. His pre-2006 district was more Republican than this, and he carried 63% of the vote in 2004.

11th: If you notice, the district is based in the inner Cobb suburbs which are pretty Democratic (Cobb only gave McCain 54% of the vote; and the most Republican parts of the county are in the 3rd, 6th, or diluted into the 5th). The tendrils go to Rome and Dalton to pick up minority populations there, to fill up the population requirements of the district without sticking to 95% white super-Republican precincts. Note that the Rome area of the district has a Democratic State Representative, even. Not quite overwhelmingly Republican. Also note that the district includes part of the extremely Democratic Atlanta city proper.

12th: Barrow wouldn't have any problem holding it. He holds his current district fine enough (66% in 2008), and the district in my map would be much safer for him. Also, the only reason Max Burns won this district in 2002 was because the Democratic candidate had huge ethical problems. Athens + Augusta + Savannah = a Democratic district, especially with the white portions of Savannah excised like they are in this map.

Still, you've got me intrigued about my 7th district here, if I have time later I'll add up precinct totals to see what the Obama/McCain vote would have been.

[Bo]

A Democratic gerrymander of Georgia! Partially inspired by the 2000-2004 map.



1st (deep blue): Safe GOP. [72% white, 21% black]
2nd (dark green): Safe DEM. [47% white, 46% black]
3rd (purple): Safe GOP. [79% white, 15% black]
4th (red): Safe/Strong lean DEM. [41% black, 41% white, 12% hispanic]
5th (yellow): Safe/strong lean DEM. [46% white, 40% black]
6th (teal): Safe GOP. [79% white]
7th (gray): lean DEM. [44% white, 24% hispanic, 21% black]
8th (bluish one in the middle): Strong lean DEM [55% white, 39% black]
9th (light blue in the north): Safe GOP [88% white]
10th (pink): Safe GOP [79% white, 12% black]
11th (light green): lean DEM. [48% white, 32% black, 16% hispanic]
12th (the eastern bluish one): Strong lean DEM [50% white, 42% black]
13th (peach/salmon): Safe DEM [51% black, 37% white]
14th (brown): Strong lean DEM [49% white, 43% black]

nine out of fourteen districts democratic!

Uh, the 11th, 7th, 8th, and 12th in that map would all Lean Republican.

7th:  Hall county Hispanics are either Strongly Republican or don't vote at all, given as that county voted 75% Republican, and Western Gwinnet county is swing territory at best for the Democrats.

8th:  The Southeastern portion of  this district is staunchly Republican, enough to more than offset any Democratic lean in the Macon part of the district.

11th: Any district based in Cobb county suburbs is going to be unwinnable for the Democrats, even more so with those tendres extending up into overwhelmingly Republican NW Georgia.

12th:  A Republican won a district with almost that exact shape a few years ago, so it's certainly not a safe district for the democrats by any stretch of the imagination.

7th: Hall County voted 75% for McCain, yes, but almost all of the remotely Democratic areas of the County are in this district- including parts of Gainesville that were >90% Obama. Four of Hall's five commissioners are elected from districts, and a Democrat holds the only district contained entirely within the 7th district on this map. A better gerrymander would have been "stringier", and cut more of the rural white southern portion of the county, but I don't think that's really necessary here. And regarding the Gwinnett, portion of the district, it's better territory for Democrats than you think. Gwinnett only voted 54.5% McCain, and the most Republican parts of the county are in the eastern half. Note that four of the eight Gwinnett State Representative districts in the 7th here are Democratic; there's only one other Democratic State Rep in the county. This isn't a district that a Democrat would have a guaranteed win in, no, but once won was elected the incumbency would be enough to keep him/her in.

8th: Marshall wouldn't have any problem holding this district. His pre-2006 district was more Republican than this, and he carried 63% of the vote in 2004.

11th: If you notice, the district is based in the inner Cobb suburbs which are pretty Democratic (Cobb only gave McCain 54% of the vote; and the most Republican parts of the county are in the 3rd, 6th, or diluted into the 5th). The tendrils go to Rome and Dalton to pick up minority populations there, to fill up the population requirements of the district without sticking to 95% white super-Republican precincts. Note that the Rome area of the district has a Democratic State Representative, even. Not quite overwhelmingly Republican. Also note that the district includes part of the extremely Democratic Atlanta city proper.

12th: Barrow wouldn't have any problem holding it. He holds his current district fine enough (66% in 2008), and the district in my map would be much safer for him. Also, the only reason Max Burns won this district in 2002 was because the Democratic candidate had huge ethical problems. Athens + Augusta + Savannah = a Democratic district, especially with the white portions of Savannah excised like they are in this map.

Still, you've got me intrigued about my 7th district here, if I have time later I'll add up precinct totals to see what the Obama/McCain vote would have been.

Where do you find the precinct data?

[Bacon King]

State SoS website.

[Bo]

State SoS website.

How do you add up the data so quickly? There are thousands of total precincts in Georgia.

[Bacon King]

State SoS website.

How do you add up the data so quickly? There are thousands of total precincts in Georgia.

lol, personally, I don't do it quickly. I added up the hundred or so Gwinnett precincts last night by hand, and it took me about an hour. I think there is a quick way using excel sheets and such but I don't know how to do that.

[Хahar 🤔]

=SUM(first cell:last cell)

[I spent the winter writing songs about getting better]

You know the sad thing about Georgia is it's quite easy to draw the new district as an R+25 and not affect the other districts much. That's probably what will happen too, I bet the new seat will run across Cherokee, Forsyth and Hall counties with also part of northern Fulton. One of the worst parts of the country, ugh.

[Verily]

You know the sad thing about Georgia is it's quite easy to draw the new district as an R+25 and not affect the other districts much. That's probably what will happen too, I bet the new seat will run across Cherokee, Forsyth and Hall counties with also part of northern Fulton. One of the worst parts of the country, ugh.

Nah, it's possible with 14 districts to draw another black majority one in the Atlanta metro, and the federal government will make them do it. They might try harder to get rid of the central/south Georgia Dems, though.

[Dgov]

Nah, it's possible with 14 districts to draw another black majority one in the Atlanta metro, and the federal government will make them do it. They might try harder to get rid of the central/south Georgia Dems, though.

Not really.  I was having trouble drawing 3 Black-majority districts in the Atlanta Area, let alone another one (Atlanta has interestingly enough, been getting whiter over the last decade).  The new district will probably cover some portion of the Atlanta Suburbs or Exurbs.

As for the Central/Southern Dems, there are a couple of ways to get rid of them.  The GOP could go the simple route and just draw Republican-leaning districts in the area (taking off a little strength from the Exurbs, you can make all 4/5 Downstate districts at least Lean Republican), or they can go the complicated route and draw another majority-black district from all the major cities there.  It would be highly messy, but I've been able to get one about 60% Black before (though it cuts from Albany to Macon to Savannah, so it might get challenged in court) that draws Sanford Bishop into it, making the whole rest of the region Solidly Republican and securing a relatively Conservative vote in the safe Democratic district.  The demographics of Georgia would make an argument for this type of district at least reasonable given that Black comprise just under a third of Georgia's population, despite there only being 2 Black-Majority districts in the state.

[Vazdul (Formerly Chairman of the Communist Party of Ontario)]

Here's my version of Georgia with 14 districts, of which 6 are black-majority. It should be noted that the black-majority districts are extremely marginal, and it would take very little difference between the estimates and reality for any of them not to be black-majority. I certainly don't submit this as a serious map, but it sure was fun to make!



CD-1 (Blue): 70% White, 22% Black, 5% Hispanic
CD-2 (Green): 50.07% Black, 34% White, 11% Hispanic
CD-3 (Purple): 71% White, 22% Black, 5% Hispanic
CD-4 (Red): 78% White, 14% Black, 5% Hispanic
CD-5 (Yellow): 51.15% Black, 34% White, 11% Hispanic
CD-6 (Teal): 75% White, 9% Black, 8% Hispanic, 7% Asian
CD-7 (Gray): 50.43% Black, 32% White, 11% Hispanic, 5% Asian
CD-8 (Light Purple): 77% White, 15% Black
CD-9 (Cyan): 50.91% Black, 34% White, 10% Hispanic
CD-10 (Magenta): 58% White, 16% Hispanic, 16% Black, 8% Asian
CD-11 (Light Green): 50.29% Black, 44% White
CD-12 (Indigo): 79% White, 11% Hispanic, 7% Black
CD-13 (Peach): 51.87% Black, 43% White
CD-14 (Bronze): 84% White, 9% Hispanic, 5% Black

NOTE: These district numbers were used because they correspond to colors that contrast well with the colors displayed when the racial demographics layer is enabled. They are not intended to correspond to the existing incumbents.

Here's a zoomed in view of the Atlanta metro area:

[Brittain33]

I know this isn't what you set out to do, but I would imagine you could give the green gerrymander district some precincts in Gwinnett County and make a more compact, viable coalition district that would elect the winner of the D primary.

[Verily]

Nah, it's possible with 14 districts to draw another black majority one in the Atlanta metro, and the federal government will make them do it. They might try harder to get rid of the central/south Georgia Dems, though.

Not really.  I was having trouble drawing 3 Black-majority districts in the Atlanta Area, let alone another one

Not true at all. It's really easy to make four; they don't even look extremely gerrymandered.

I suspect the actual Census data will make it even easier as (a) Dave's Redistricting uses 2008 estimates, and the growth of the black population in some suburban counties has been phenomenal and (b) Dave's Redistricting assumes uniform change in population across counties, when of course very few blacks are moving in to outer Cobb/Gwinett/Newton/Rockdale/Henry/Douglas counties. As a result the actual growth in the black population will be more concentrated in the areas in the districts I drew than in the areas in those counties outside of my districts.

One example, with some wiggle room at the edges.

[JohnnyLongtorso]

Here's a Republican map of Pennsylvania, losing a district from the current map. Tried not to overreach too much; concentrated on protecting incumbents and watering down a couple of districts, rather than trying to maximize Republican seats.



Click for bigger.

PA-01 (blue Philly district, Bob Brady - D) - Expands to take in more of Delaware County, uber-safe for the Dems.
PA-02 (green Philly district, Chaka Fattah - D) - Mostly unchanged; still majority-black. Obviously uber-safe.
PA-03 (purple NW corner district, Kathy Dahlkemper - D) - Pushes east instead of south, taking in some heavily-Republican counties. Should make the district more Republican.
PA-04 (red SW district, Jason Altmire - D) - Takes in all of the Dem-leaning areas outside of Pittsburgh. Should be safe for Altmire.
PA-05 (orange central district, Glenn Thompson - R) - Takes in a bunch of the Philly suburbs in Westmoreland County instead of the NW counties, which shouldn't change the partisan balance much.
PA-06 (teal SE PA district, Jim Gerlach - R) - Tried to make this district as safe as possible, so it takes in all the Republican parts of Montgomery and Bucks now. Should be a Republican-leaning district now.
PA-07 (grey SE PA district, open) - Pushed west in order to make it less Democratic. Still a swing district, but should be more favorable to the Republicans.
PA-08 (purple SE PA district, Patrick Murphy - D) - Takes in all the Dem parts of Bucks, and parts of Montgomery and Philadelphia. Safe Dem seat.
PA-09 (light blue SW PA district, Bud Shuster - R and Mark Critz - D) - Swallows parts of Critz's district, which tilts the district from "overwhelmingly Republican" to just "very Republican". Shuster would prevail in a matchup with Critz.
PA-10 (magenta NE PA district, Chris Carney - D) - Carney's district is completely reconfigured as a safe Dem district, taking in all of Lackawanna along with Bethlehem, Scranton, and part of Allentown.
PA-11 (green NE PA district, Paul Kanjorski - D) - Turns Kanjo's district (since he's probably going to lose to Barletta) into a pretty Republican one. Shouldn't be hard for Barletta to hold in 2012.
PA-12 (light purple SE PA district, Todd Platts - R) - Takes in Harrisburg, which makes the district a little less Republican, but it shouldn't be hard for Republicans to hold.
PA-13 (pink SE PA district, Alyson Schwartz - D) - Heavily-Democratic MontCo-based district.
PA-14 (brown SW PA district, Mike Doyle - D) - Heavily-Democratic Pittsburgh district.
PA-15 (orange NE PA district, Charlie Dent - R) - With Bethlehem and most of Allentown gone, the district picks up some Republican-leaning counties that should make it easier for Dent to hold.
PA-16 (green SE PA district, Joe Pitts - R) - Mostly Lancaster County, takes in some Dem parts of Berks and Chester, but should remain Republican-leaning.
PA-17 (dark purple SE PA district, Tim Holden - D) - Getting rid of Tim Holden requires chopping up Schuylkill County, and also removes Harrisburg. Should be even more Republican now.
PA-18 (yellow SW PA district, Tim Murphy - R) - Takes in a bunch of Republican-leaning parts of SW PA. Maybe a little less Republican, but still Republican. Republican!

[I spent the winter writing songs about getting better]

Something I just noticed, South Carolina is about 30% black, so with 7 districts proportionally that would require another majority black seat. Will the Justice Department force one?

Georgia is too easy for the Republicans, just draw a new Republican seat in metro Atlanta and a majority black seat downstate, thus removing Marshall and Barrow.

[muon2]

Here's a Republican map of Pennsylvania, losing a district from the current map. Tried not to overreach too much; concentrated on protecting incumbents and watering down a couple of districts, rather than trying to maximize Republican seats.



Click for bigger.

PA-01 (blue Philly district, Bob Brady - D) - Expands to take in more of Delaware County, uber-safe for the Dems.
PA-02 (green Philly district, Chaka Fattah - D) - Mostly unchanged; still majority-black. Obviously uber-safe.
PA-03 (purple NW corner district, Kathy Dahlkemper - D) - Pushes east instead of south, taking in some heavily-Republican counties. Should make the district more Republican.
PA-04 (red SW district, Jason Altmire - D) - Takes in all of the Dem-leaning areas outside of Pittsburgh. Should be safe for Altmire.
PA-05 (orange central district, Glenn Thompson - R) - Takes in a bunch of the Philly suburbs in Westmoreland County instead of the NW counties, which shouldn't change the partisan balance much.
PA-06 (teal SE PA district, Jim Gerlach - R) - Tried to make this district as safe as possible, so it takes in all the Republican parts of Montgomery and Bucks now. Should be a Republican-leaning district now.
PA-07 (grey SE PA district, open) - Pushed west in order to make it less Democratic. Still a swing district, but should be more favorable to the Republicans.
PA-08 (purple SE PA district, Patrick Murphy - D) - Takes in all the Dem parts of Bucks, and parts of Montgomery and Philadelphia. Safe Dem seat.
PA-09 (light blue SW PA district, Bud Shuster - R and Mark Critz - D) - Swallows parts of Critz's district, which tilts the district from "overwhelmingly Republican" to just "very Republican". Shuster would prevail in a matchup with Critz.
PA-10 (magenta NE PA district, Chris Carney - D) - Carney's district is completely reconfigured as a safe Dem district, taking in all of Lackawanna along with Bethlehem, Scranton, and part of Allentown.
PA-11 (green NE PA district, Paul Kanjorski - D) - Turns Kanjo's district (since he's probably going to lose to Barletta) into a pretty Republican one. Shouldn't be hard for Barletta to hold in 2012.
PA-12 (light purple SE PA district, Todd Platts - R) - Takes in Harrisburg, which makes the district a little less Republican, but it shouldn't be hard for Republicans to hold.
PA-13 (pink SE PA district, Alyson Schwartz - D) - Heavily-Democratic MontCo-based district.
PA-14 (brown SW PA district, Mike Doyle - D) - Heavily-Democratic Pittsburgh district.
PA-15 (orange NE PA district, Charlie Dent - R) - With Bethlehem and most of Allentown gone, the district picks up some Republican-leaning counties that should make it easier for Dent to hold.
PA-16 (green SE PA district, Joe Pitts - R) - Mostly Lancaster County, takes in some Dem parts of Berks and Chester, but should remain Republican-leaning.
PA-17 (dark purple SE PA district, Tim Holden - D) - Getting rid of Tim Holden requires chopping up Schuylkill County, and also removes Harrisburg. Should be even more Republican now.
PA-18 (yellow SW PA district, Tim Murphy - R) - Takes in a bunch of Republican-leaning parts of SW PA. Maybe a little less Republican, but still Republican. Republican!

This reminds me a lot of what IL did in 2001 when the districts were designed for incumbent protection with one seat lost. If that's the case, I would expect that the loser is the one who lacks political support, happened to Phelps in IL. Is Critz the most likely loser? How much will it depend on the Gov next year?

[I spent the winter writing songs about getting better]

I've also played around with Illinois to see who the loser will be. I think Schock and Shimkus end up in the same seat. Also shoring up Halvorson and Foster isn't too hard (especially Foster, just swap that swath of rural counties on the western tail of his district for Rockford.)

[Smash255]

Here's a Republican map of Pennsylvania, losing a district from the current map. Tried not to overreach too much; concentrated on protecting incumbents and watering down a couple of districts, rather than trying to maximize Republican seats.



Click for bigger.

PA-01 (blue Philly district, Bob Brady - D) - Expands to take in more of Delaware County, uber-safe for the Dems.
PA-02 (green Philly district, Chaka Fattah - D) - Mostly unchanged; still majority-black. Obviously uber-safe.
PA-03 (purple NW corner district, Kathy Dahlkemper - D) - Pushes east instead of south, taking in some heavily-Republican counties. Should make the district more Republican.
PA-04 (red SW district, Jason Altmire - D) - Takes in all of the Dem-leaning areas outside of Pittsburgh. Should be safe for Altmire.
PA-05 (orange central district, Glenn Thompson - R) - Takes in a bunch of the Philly suburbs in Westmoreland County instead of the NW counties, which shouldn't change the partisan balance much.
PA-06 (teal SE PA district, Jim Gerlach - R) - Tried to make this district as safe as possible, so it takes in all the Republican parts of Montgomery and Bucks now. Should be a Republican-leaning district now.
PA-07 (grey SE PA district, open) - Pushed west in order to make it less Democratic. Still a swing district, but should be more favorable to the Republicans.
PA-08 (purple SE PA district, Patrick Murphy - D) - Takes in all the Dem parts of Bucks, and parts of Montgomery and Philadelphia. Safe Dem seat.
PA-09 (light blue SW PA district, Bud Shuster - R and Mark Critz - D) - Swallows parts of Critz's district, which tilts the district from "overwhelmingly Republican" to just "very Republican". Shuster would prevail in a matchup with Critz.
PA-10 (magenta NE PA district, Chris Carney - D) - Carney's district is completely reconfigured as a safe Dem district, taking in all of Lackawanna along with Bethlehem, Scranton, and part of Allentown.
PA-11 (green NE PA district, Paul Kanjorski - D) - Turns Kanjo's district (since he's probably going to lose to Barletta) into a pretty Republican one. Shouldn't be hard for Barletta to hold in 2012.
PA-12 (light purple SE PA district, Todd Platts - R) - Takes in Harrisburg, which makes the district a little less Republican, but it shouldn't be hard for Republicans to hold.
PA-13 (pink SE PA district, Alyson Schwartz - D) - Heavily-Democratic MontCo-based district.
PA-14 (brown SW PA district, Mike Doyle - D) - Heavily-Democratic Pittsburgh district.
PA-15 (orange NE PA district, Charlie Dent - R) - With Bethlehem and most of Allentown gone, the district picks up some Republican-leaning counties that should make it easier for Dent to hold.
PA-16 (green SE PA district, Joe Pitts - R) - Mostly Lancaster County, takes in some Dem parts of Berks and Chester, but should remain Republican-leaning.
PA-17 (dark purple SE PA district, Tim Holden - D) - Getting rid of Tim Holden requires chopping up Schuylkill County, and also removes Harrisburg. Should be even more Republican now.
PA-18 (yellow SW PA district, Tim Murphy - R) - Takes in a bunch of Republican-leaning parts of SW PA. Maybe a little less Republican, but still Republican. Republican!

This reminds me a lot of what IL did in 2001 when the districts were designed for incumbent protection with one seat lost. If that's the case, I would expect that the loser is the one who lacks political support, happened to Phelps in IL. Is Critz the most likely loser? How much will it depend on the Gov next year?

Thats part of it, but it also depends on population factors.  Its very hard for the lost seat to come from anywhere other than western PA.  The Philly proper districts have lost the most population, but the surrounding areas have generally gained the most, so that basically cancels each other out and makes it difficult to cut a district there.  The Appalachia areas in western PA have been bleeding population.