2020 Redistricting in Pennsylvania

[Former President tack50]

Ok, so here is a quick map I have just drawn with 17 districts roughly based on the current ones and deleting the 15th district. I think it uses 2010 estimates which means the population distribution is probably wrong but whatever. Opinion?

I don't really like splitting big cities, but Pittsburgh is just perfectly designed to be split 3 ways along the rivers in the town Plus it doesn't change the partisanship of the 3 districts anyways (one solid D, one tossup and one solid R; though the solid D district goes to more like Likely D)

Numbers are 2016 election numbers



Pittsburgh closeup



Philadelphia closeup



From what I can tell this map would be something like this?

4 Safe D
2 Lean D
2 Tossup
9 Safe R (maybe 2 would be Likely R?)

So probably not a fair map and a bit of an R gerrymander, though I guess the beyond titanium D 2nd and 3rd districts sink the chances of Democrats here?

[Former President tack50]

Annoyingly, a fair 17-district map in PA only produces 5 Safe D districts (2 in Philly, MontCo, DelCo, and Pittsburgh.) You may not like it (I certainly don't) but this is what peak fair map performance looks like:

Hate to beat this CRR drum here, but imagine what could be done with ~28 seats?

PA has a problem since all of its D votes are packed into tight little circles, so larger districts done without spaghetti strips drowns them all out. Smaller districts on the other hand make things more interesting.

Doesn't really change all that much?

The problem for Democrats is really that US cities now vote like they belong in North Korea or Saddam Hussein's Irak (80-20 or more); while the Republican areas are more numerous and vote on the scale of 60-40 (comfortable victories, but without wasting votes)

A hypothetically fair 28 district map might look something like this



This map would have 8 "bomb proof" Democratic seats (6 in the Philadelphia area, 1 Allentown and 1 Pittsburgh); as well as 3-4 others that would be a heavy lift for an R candidate but aren't truly safe (D+2 PVI).

Blairite's map gives Dems 29% of the seats in "bombproof" seats. This map gives them 29% as well. The main difference is that instead of a bunch of Lean R seats, after that you get several Lean D seats instead.

Overall I don't think it makes a particular difference to increase the number of seats (depends on the state)

[Former President tack50]

Looking at Sev's map, I guess that is more of a "best case scenario for Dems in court" than anything else.

Much of the map is acceptable or tolerable, but there are some complaints I'd have:

1) The Pittsburgh area split isn't "right". You shouldn't split the city, and there should be a southwestern district

2) Districts 2, 5 and 6 should be changed to make them less elongated.

[Former President tack50]

Given the big discussion, here is my attempt at a fair map:



https://davesredistricting.org/join/d1ee3bc5-f0df-4366-a9dc-e796ce5a6ac1

PA-01: Clinton+1, R+1
PA-02: Clinton+64, D+32 (41% black, 32% white, 22% hispanic)
PA-03: Clinton+80, D+39 (55% black)
PA-04: Clinton+23, D+8
PA-05: Clinton+17, D+6
PA-06: Trump+5, R+3
PA-07: Clinton+0, EVEN
PA-08: Trump+12, R+2
PA-09: Trump+16, R+8
PA-10: Trump+43, R+19
PA-11: Trump+19, R+11
PA-12: Trump+10, R+7
PA-13: Trump+45, R+22
PA-14: Trump+31, R+14
PA-15: Trump+35, R+16
PA-16: Trump+22, R+9
PA-17: Clinton+29, D+14

In theory this should be a map with 5 Titanium D districts, 6 titanium R districts, 3 tossups and 2 districts that are heavily R but are as of now held by Dems (you could consider those R districts, Trump did win by double digits after all).

Overall, a 5D-8R-3S map. Not the fairest thing in terms of party numbers, but as in many other states geography goes against Dems here, who are concentrated to a large degree in supermajority dem districts in Philadelphia.

And as when doing a fair map, here is my attempt at identifying the COI represented:

PA-01: Bucks & North Philadelphia
PA-02: Central Philadelphia
PA-03: South Philadelphia, Philadelphia black VRA district
PA-04: Montgomery County
PA-05: Delaware County & East Chester County
PA-06: Berks & West Chester County
PA-07: Allentown area
PA-08: Scranton & Wilkes-Barre area / Northwest PA
PA-09: Harrisburg
PA-10: North central rural PA
PA-11: Lancaster & East York (tried to have York city in this district, but many suburbs had to be left out unfortunately)
PA-12: West Pittsburgh suburbs and Beaver County
PA-13: South central rural PA
PA-14: Southwest PA
PA-15: North Central Rural PA (but to the west of PA-10)
PA-16: Erie area & Northwest PA
PA-17: Pittsburgh & East Pittsburgh suburbs

[Former President tack50]

For fun, I decided to do an R gerrymander, just to see how bad it would be for Democrats. The answer is "very bad". It is not the best gerrymander out there (the numbers are there to make the swing seat be a Trump / R PVI district at the very least) but it is good enough



In order to keep things safe, I decided to make all Trump districts won by at least double digits and to be at least R+5.

If my calculations are correct, this should work as a 13R-1S-3D map; with only 3 Philly area dems keeping seats, one swingy seat in Bucks (just like now) and the rest becoming Safe R

PA-01: Clinton+32, D+12
PA-02: Clinton+76, D+37 (46% black)
PA-03: Clinton+74, D+37 (52% black)
PA-04: Clinton+4, D+1
PA-05: Trump+11, R+6
PA-06: Trump+11, R+7
PA-07: Trump+12, R+7
PA-08: Trump+16, R+6
PA-09: Trump+19, R+6
PA-10: Trump+25, R+11
PA-11: Trump+16, R+8
PA-12: Trump+15, R+9
PA-13: Trump+16, R+6
PA-14: Trump+11, R+6
PA-15: Trump+13, R+8
PA-16: Trump+17, R+8
PA-17: Trump+16, R+8

Granted, if you use the 2018 maps for Governor or Senator the map falls apart completely, with the Democratic candidates flipping most Congressional districts. Scott Wagner for Governor only wins districts 9 and 10; the former by only around 400 votes. Lou Barletta for Senate does a bit better and wins in districts 8, 11 and 12 as well (though in this case districts 6, 7 and 16 are won by incredibly narrow margins; within 0.5%)

Given PA-02 is 46% black and PA-03 is 52% black; I wonder if Republicans could cynically sue in order to create 2 black districts in Philadelphia; or if suing like that would benefit them in some way.