Big Redistricting News Out Of PA!

[Southern Senator North Carolina Yankee]

If this gets through, it's huge. I could both Harrisburg and Erie-based districts that are tossups at worst for Democrats. There may even be a competitive Lancaster-based district.

Democrats are losing ground in Erie. It voted for Trump, Toomey and just last week for Mundy. All the counties around it are solidly Republican (60%+ solid) and it doesn't have enough population on its own. If PA loses a district in 2020, there position will get even worse because it would need even more heavily Republican counties meet population requirement.

Many aspects of the GOP gerrymander are now unnecessary and irrelevant. And frankly Republicans would probably be better off tossing a district in SE PA at this juncture, because the house of cards in that region is looking shaky, just like the PA-13 game they played in 2002 and absent a redraw it could backfire in 2018 just as that did in 2006.

[Southern Senator North Carolina Yankee]

The districts in the Philly suburbs are ridiculously gerrymandered and I've long felt that the GOP should simply concede one more district to the dems in southeast PA. On the other hand, PA 17 was drawn as a democrat vote sink and Trump still won it in 2016. A fairly drawn PA 17 would probably have to include all of Luzcerne and Lackawanna counties while Easton is given back to Lehigh Valley based PA 15. If this were the case, the district would lean R. The truth is that, as a result of democrats being so concentrated in Philly, it would take an extreme gerrymander to even have 7 democrat districts out of 18. PA will lose a district after the 2020 census anyway (maybe even two) so this seems like a waste of time for one or two elections at most.

Well historically PA-11 was based around Luzerne while PA-17 was centered around Harrisburg. Hilarious, if that strategy is followed, PA-17 becomes the Luzerne seat while 11 becomes the seat in Harrisburg metro. PA-17 only began its march eastward in 2002, when they merged it with Holden's Schuylkill county based PA-06 in the hopes of knocking out Holden and creating a new PA-06 for then State Senate Jim Gerlach. The latter succeeded, but the former failed, and Holden held that version of PA-17 all the way until the new map in 2012.

PA-10 and PA-11 have been in NE PA for like, ever. PA-10 was Lackawanna County, and PA-11 was Luzerne. Following the 1950 census, PA-10 inherited the rural NE PA counties from a heavily Republican district that was dismantled. Scranton was only removed in 2002 following the close call in 1998 in PA-10.

[Southern Senator North Carolina Yankee]

The districts in the Philly suburbs are ridiculously gerrymandered and I've long felt that the GOP should simply concede one more district to the dems in southeast PA. On the other hand, PA 17 was drawn as a democrat vote sink and Trump still won it in 2016. A fairly drawn PA 17 would probably have to include all of Luzcerne and Lackawanna counties while Easton is given back to Lehigh Valley based PA 15. If this were the case, the district would lean R. The truth is that, as a result of democrats being so concentrated in Philly, it would take an extreme gerrymander to even have 7 democrat districts out of 18. PA will lose a district after the 2020 census anyway (maybe even two) so this seems like a waste of time for one or two elections at most.

Interestingly as shown by Moun's district above, the 2010 numbers really encourage PA-17 to be Luzerne+Lackawanna+Monroe - the three counties are only a few hundred voters off of baseline. Such a district would be 51.7-44.6 Trump, compared to the current districts 54-43. It would have a Even PVI whereas the current district has a R+1. The thing really anchoring Pubs in the current PA-17 is Schuylkill, the one real remnant of the 2000 PA-17. The county was Tim Holden's base, and so it was grafted on to all the former Dem areas of PA-11.

The thing about PA is that the geography really favors the Pubs. Most fair maps can really only get 10/11 Obama districts out of a state Obama won by 10%. A 2012/2016 fair map of PA typically has:

-5 Solid Blue Districts: 4 in Philly Metro and one in Philly
-4 Marginal districts:  two in Metro, one in Lehigh valley, one in Northeast - my maps tend to have these all never leave a D+1/R+1 margin
-1 rarely competitive R seat somewhere with a R+5/6/7 PVI
-8 Safe Republican Seats across the state.

A fair map only really gives the Dems one seat, and pushes the four remaining swing seats closer to the center. The state favors the Pubs, and if this wasn't looking like a Democratic year, a fair map might not really change the state arithmetic.

This is a marked shift from the 2000's map, where it definitely was gerrymandering that made the difference to produce a 12-7 GOP Map in a state that voted for Gore and Kerry. We are really worlds away from a Democratic district being anchored in Somerset and Cambria County for instance (Murtha's) and 4 Democratic Districts to the West of it. PA-04 (Lawrence/Beaver based seat), PA-12 (Murtha), PA-14 (Pittsburgh, PA-18 (Pittsburgh and suburbs), PA-20 (WV Border Counties) were all Dem held seats in Western PA in the 1990's and PA-21 (Erie Based) could have been if not for Phil English and Tom Ridge before him.

[Southern Senator North Carolina Yankee]

Or a new swing seat in a court-drawn map where Chester has a D+ PVI. What a time to be alive

Chester is interesting - in 2008/2012 the county was easily still to the right of the state. In 2016 the county swung very hard to to the left, and it looks to be staying that way. Democrats appear to have made strides in the row offices last week, and the county backed the failed Liberal bid at the Supreme court, even while the Liberal Judge lost Lakawanna, Erie, and Lehigh all went for the Conservative. For reference, the race was 52-47 Conservative Judge.

The weird thing is that when drawing fair districts in that region of PA, there is a Gordian Knot in the lines. You have the numbers for two districts (6/16) and a few extraneous pops to balance out the 13th or the 7th. However, the counties make things nice. Of Chester, Berks, and Lancaster, only two can get a district based around them. The third has to get brutally cut up between her neighbors. There is no way to avoid it. We have a map in this thread that cuts Chester, and a map that cuts Lancaster - and I always have liked to cut Berks. There is no real solution which is the better county to cut.

If two chops are needed and the chop is inevitably large, eg more than 5% of the district population, I find that the shapes can be best managed by putting both chops in one county. Metrics that look at chops sometimes build that in intentionally. For instance FL looks at how many counties are chopped, not how many chops are required and that forces all the chops into a few counties if applied rigorously.

Leaving aside the flawed numbers, I like how your map above looks in terms of PA-16 and PA-06. I also liked that you kept 11 in the NE and put 17 back where it belongs.

I would note that by splitting Lancaster, from my birds eye view, has the effect of a soft pro-GOP gerrymander, since Lancaster is traditionally Republican (though ebbing), putting a chunk in with a Chester based PA-06 and a Berks based PA-16, has the effect of tilting both to the Republicans in too steep way for either to flip. Whereas Lancaster plus a piece of Chester, would be Safe Republican for at least a while, while a Berks plus rest of Chester seat would actually be competitive.

[Southern Senator North Carolina Yankee]

Or a new swing seat in a court-drawn map where Chester has a D+ PVI. What a time to be alive

Chester is interesting - in 2008/2012 the county was easily still to the right of the state. In 2016 the county swung very hard to to the left, and it looks to be staying that way. Democrats appear to have made strides in the row offices last week, and the county backed the failed Liberal bid at the Supreme court, even while the Liberal Judge lost Lakawanna, Erie, and Lehigh all went for the Conservative. For reference, the race was 52-47 Conservative Judge.

This not completely new, I would note that a lot of gains were made in SE PA in 2005-2008, in Montco, Delco and Bucks. Chester seems to have the makings of a shift to the Democrats demographically, but I wouldn't read a lot into local level sweeps in an off year for the party not in power. Remember in 2009, the Republicans gained the school board in Wake County, NC leading to that big fight over community schools/busing. You have to pare back and separate cyclical decline and structural, and recognize that a lot of places that were once formerly Republican strongholds are now swing areas and vice versa. So you are going to see these kind of results that shift unfolds. Some areas will become solid for the other party.

[Southern Senator North Carolina Yankee]

Iowa is good by American standards but it isn't really that good compared to the rest of the world. In fact it's a great example of my point. The Des Moines urban area is split between all four congressional districts, while if you just split a single county then all of Des Moines could be united in one single congressional district. In the same vein Western Iowa is also split between two districts, when it could easily be united as one.

"urban area" has a quite specific meaning in the United States census. You may be using some entirely different meaning. What is the name of that county that you believe if it were split would unify Des Moines in a single congressional district.

If western Iowa were in a single district, as it was during the 2000s, what would the other three look like? Some of the others during the 2000s were ugly.

Because I am to lazy to draw my own this very second I'll just borrow a map from Dailykos:

Unfortunately for DK, IA has a very strict requirement to keep counties whole. The split county in this map does nothing to keep communities of interest whole. It does serve the political agenda of DK by packing the most conservative parts of the state into a single CD. This is what I mean by my concern over the lack of firm criteria; using soft standards invites subtle gerrymandering.

And Iowa has one of the best redistricting processes in the country.

[Southern Senator North Carolina Yankee]

I will say again, Iowa has one of the best redistricting processes in the country in that it has no gerrymandering, nor the possibility of such. Any changes better be damn careful not to screw that up.