2020 Redistricting in Pennsylvania

[kwabbit]

Other posters have said that the split government in PA would lead to a non-partisan court drawn map?

Would that court have any pro-incumbent tendencies, i.e. giving Fitzpatrick redder parts of Montgomery/saving Lamb?

On that note, is there any reasonable way Lamb could be given a reasonably winnable seat without a pro-inc / Dem gerrymander? Most variations I see have Lamb's seat at around Trump +5 in 2020. Not that he couldn't win that, but he barely overperformed Biden this year and it seems like he is no longer above the partisan lean of his district a la his 2018 special election.

[kwabbit]

[...]

On that note, is there any reasonable way Lamb could be given a reasonably winnable seat without a pro-inc / Dem gerrymander? Most variations I see have Lamb's seat at around Trump +5 in 2020. Not that he couldn't win that, but he barely overperformed Biden this year and it seems like he is no longer above the partisan lean of his district a la his 2018 special election.

Depending on whether you consider the 2018 court map a Dem gerrymander or not in the Pittsburgh area, it is very easy to give Lamb a reasonably winnable seat:
- The line between Lamb's seat and the Pittsburgh seat in Allegheny county stays exactly as it is.
- The Pittsburgh seat takes in parts of e.g. Westmoreland county from the current 14th.
- The current 14th will include Washington, Green, Fayette, Somerset and most of Westmoreland. In fact the only county split of the successor of the 14th would be in Westmoreland with the Pittsburgh seat, hence avoiding an unnecessary county split.
- Lamb's seat could be extended into Butler or Lawrence.

An extension into Butler would move Lamb's seat from Trump +2.53 to Trump +4.26, going by 2016 results. An extension into Lawrence could move Lamb's seat to as low as Trump +3.26. I don't have 2020 numbers, but given that Lamb won by 2.2, his margin would go to ca. 0.5-1.5 percentage points.

I see. I don't consider the current map a Dem gerrymander, but of all the fair maps possible, it is definitely a more Dem-favorable configuration.

My assumption was that the Pittsburgh seat would stay entirely in Allegheny, and in the process it would take in most of the Dem-friendly inner suburbs, thereby hurting Lamb. If it does expand into Westmoreland instead, then it would leave room for Lamb to take in the friendly suburbs that have supplied him his past victories.

https://davesredistricting.org/join/7451cc49-5088-4dea-95f2-d89dbea3c030

This was my take. I started with Pittsburgh and then tried to take in the rest of Allegheny whilst making it compact. If compactness and not trying to split Westmoreland is a priority, then I don't really see Lamb getting a favorable seat.

[kwabbit]

Would that court have any pro-incumbent tendencies, i.e. giving Fitzpatrick redder parts of Montgomery/saving Lamb?

The court-appointed special master in 2018 seemed to make minimizing county/municipal splits the top priority, with partisan proportionality a secondary goal. There wasn't a particular effort to protect incumbents - in fact, Fitzpatrick's district took in bluer parts of MontCo compared to the pre-2018 lines.

Well, I would expect any marginal district in PA to have gotten more blue as they drew a non-gerrymandered map. I guess the question is completely forward looking as the court has never drawn a map from scratch, as in never without the purpose of resolving a partisan gerrymander.

[kwabbit]

Would that court have any pro-incumbent tendencies, i.e. giving Fitzpatrick redder parts of Montgomery/saving Lamb?

The court-appointed special master in 2018 seemed to make minimizing county/municipal splits the top priority, with partisan proportionality a secondary goal. There wasn't a particular effort to protect incumbents - in fact, Fitzpatrick's district took in bluer parts of MontCo compared to the pre-2018 lines.

Well, I would expect any marginal district in PA to have gotten more blue as they drew a non-gerrymandered map. I guess the question is completely forward looking as the court has never drawn a map from scratch, as in never without the purpose of resolving a partisan gerrymander.

Here's the thing - Fitzpatrick's old district was the rare one that wasn't gerrymandered. It was compact and contained all of Bucks County. No one would have batted an eye if the court had kept that district exactly the same. Instead, the special master made a conscious choice to favor partisan proportionality at the expense of incumbent protection.

Hmm. Does the court have an explicit goal of partisan proportionality, or is that inferred from the lines it draws? I don't know if the courts have explicit goals or if they essentially just release a map and that's that.

Pennsylvania in a fair map will be favorable for Republicans because of its political geography; I would expect 9 R/ 8D in a baseline scenario, perhaps even 10 R / 7D in a 17 district map. Will the court attempt 9D / 8R, which might be the most proportional in terms of partisanship?

[kwabbit]

I tried my hand at a fair congressional map of Pennsylvania using the 2020 census results.

Image Link

The Population Deviation is less than 0.01%.

57/100 on Dave's Proportionality Index
69/100 on the Compactness Index
36/100 on County Splitting
50/100 on the Minority Representation index
33/100 on Dave's competitiveness index

The map above shows results from the 2020 U.S. Presidential election in Pennsylvania.

Check it out here and see county and municipality boundaries.


Partisan Breakdown by Election

2016 Pennsylvania Attorney General Election: 10R to 7D

2016 U.S. Senate Election in Pennsylvania: 12R to 5D

2016 U.S. Presidential Election in Pennsylvania: 11R to 6D

2018 U.S. Senate Election in Pennsylvania: 11D to 6R

2018 Pennsylvania Gubernatorial Election: 11D to 6R

2020 Pennsylvania Attorney General Election: 9D to 8R

2020 U.S. Presidential Election in Pennsylvania: 9R to 8D


Got two plurality-Black seats in Philly. One at 45.8% VAP and 44.6% VAP.
Surprised nobody else is doing that and the current map doesn't have that, it was really easy to draw.


Opinions?

Excuse me, any map that isn't a light Dem gerrymander in the Pittsburgh area is unfair.

/s

Looks pretty good, PA doesn't have that many variations in how to draw it fairly, however you did some interesting things with Pittsburgh and Harrisburg. Interesting that you drew the rest of Allegheny into the SW corner instead of pairing it with Beaver and Butler.

I don't think people are drawing the two Black seats in Philadelphia because they have trouble detaching their idea of fairness from the current map. Brendan Boyle, a White guy, is the representative from that side of Philly so the prevailing assumption is that the North Philly seat isn't to be drawn as a VRA seat and that Evan's seat should take the lion's share of Black voters.

The same bias is what's poisoning thought around Lamb's seat. Without regard to any partisan metric, the most compact, fair version of that seat would be around Trump +5. But since the current seat is a moderate Dem gerrymander and still seems reasonable, most posters here are gravitating towards keeping it intact or even shoring up Lamb as their idea of fair.

The whole redistricting process in PA is screwed up along these lines. I understand that a lot of Democrats have become bitter to completely neutral map-drawing because of Republican gerrymanders, but the PA court drawing isn't benevolent or in good-faith. The fact that it can be lobbied by the incumbents and takes into account their demands isn't good government, even if the end result is only a moderate Dem gerrymander.

[kwabbit]

PA Proportional Attempt

I tried to emulate the court by making it 8.5-8.5 essentially and keeping all incumbents (that aren't running for higher office) in their current districts. Cartwright is pretty screwed, him and Wild can't both survive. Just not enough Dem territory left.

[kwabbit]

PA Proportional Attempt

I tried to emulate the court by making it 8.5-8.5 essentially and keeping all incumbents (that aren't running for higher office) in their current districts. Cartwright is pretty screwed, him and Wild can't both survive. Just not enough Dem territory left.

The 3rd should be Black-majority. 43% VAP isn't cutting it when the population is this concentrated.

Splitting Forest County, which has less than 6,000 people, gave me a good laugh.

I was trying to keep Delaware County whole, with hopefully both of the Philadelphia districts being Black districts. You kind of have to extend into the Black part of Delaware to get a higher Black percentage if you want two Black-performing seats, especially if the Bucks-based district extends into Montgomery instead of NE Philly.

For some reason I like splitting tiny counties more than big ones lol. Idk it feels like a county of 6k people doesn't form enough of a community where it shouldn't be split, but larger counties do. It makes a nice straight line too.

[kwabbit]

Is a court really going to split Pittsburgh? I get that proportionality is a goal, but splitting a city of 300k to help Democrats is too far past what a non-partisan body should attempt even if proportionality is a goal. Fine, give Lamb's district every Dem-leaning suburb, but at least respect an important municipal line.

[kwabbit]

Is a court really going to split Pittsburgh? I get that proportionality is a goal, but splitting a city of 300k to help Democrats is too far past what a non-partisan body should attempt even if proportionality is a goal. Fine, give Lamb's district every Dem-leaning suburb, but at least respect an important municipal line.

I have my doubts. Which is why I would've preferred that Wolf propose something like this:

https://twitter.com/PAMapper/status/1485818368590557185

I believe the GOP congressman for Western PA, Mike Kelly, is from Butler so I doubt they would draw him out of his district. I was able to make two Dem districts in the Pittsburgh area through Beaver, parts of Washington including the city of Washington, the geographical Northwestern half of Allegheny then stretching into the Black eastern suburbs of Pittsburgh. Mt. Lebanon and all of Southern Allegheny would be in the Pittsburgh seat in this scenario.

[kwabbit]

I believe the GOP congressman for Western PA, Mike Kelly, is from Butler so I doubt they would draw him out of his district. I was able to make two Dem districts in the Pittsburgh area through Beaver, parts of Washington including the city of Washington, the geographical Northwestern half of Allegheny then stretching into the Black eastern suburbs of Pittsburgh. Mt. Lebanon and all of Southern Allegheny would be in the Pittsburgh seat in this scenario.

If Democrats are proposing maps to the courts, I don't think they should be trying especially hard to protect Mike Kelly.

I drew the Washington County district the way I did for compactness reasons (in order to make it more appealing to the courts).

That's true, but Kelly's district remaining intact allows for least change to be argued. Even a Dem leaning court will show some deference to Republican incumbent legislators. All of these people know each other and won't want to anger a colleague even on the other side of the aisle.

[kwabbit]

Changes from 2020

PA-01: Biden +5.8 to Biden +4.6
PA-02: Biden +41.0 to Biden +42.7
PA-03: Biden +83.2 to Biden +80.9
PA-04: Biden +24.1 to Biden +18.9
PA-05: Biden +31.1 to Biden +32.3
PA-06: Biden +15.0 to Biden +14.8
PA-07: Biden +4.8 to Biden +0.6
PA-08: Trump +4.4 to Trump +2.9
PA-10: Trump +2.9 to Trump +4.1

Good for PA-08 but crappy for PA-07, while Dean is losing a chunk of Dems - where did they go? Are those the ones going to PA-05? Because that district is only 1% more Dem.

PA-01 and PA-10 kinda suck. Little to no chance that Dems can get those back even in a good year at this point with Fitz and now that PA-10 is more GOP and Perry won more than Trump in 2020.

You forgot the most important change, R's lose an entire seat yet 3/4 Dem swing seats get shored up.

Right, but the GOP should lose a seat. They have the most population loss and they lost the state in 2020.

That was always agreed upon since the begining of this cycle. The Democratic seats still needed to pick up 300k in population of blood red territory. Considering 3/4 swing seats for Democrats got shored up despite that, that's a swell courtmander they got.

https://davesredistricting.org/maps#viewmap::48bc041f-ff25-42bc-a74d-d90f325dde0e

Look at Palandios map. Democrats gain like 14 points from PA17 moving it from somewhere around Trump +8 to Biden +6. They gain like 10 points for PA06 with the tri chop of Berks to drown it out with Montgomery and Chester. . That's a whole 25 points worth gained in swing districts .

It's a neutral map in wbrock67's alternate reality where Biden actually won PA by 9.

[kwabbit]

Changes from 2020

PA-01: Biden +5.8 to Biden +4.6
PA-02: Biden +41.0 to Biden +42.7
PA-03: Biden +83.2 to Biden +80.9
PA-04: Biden +24.1 to Biden +18.9
PA-05: Biden +31.1 to Biden +32.3
PA-06: Biden +15.0 to Biden +14.8
PA-07: Biden +4.8 to Biden +0.6
PA-08: Trump +4.4 to Trump +2.9
PA-10: Trump +2.9 to Trump +4.1

Good for PA-08 but crappy for PA-07, while Dean is losing a chunk of Dems - where did they go? Are those the ones going to PA-05? Because that district is only 1% more Dem.

PA-01 and PA-10 kinda suck. Little to no chance that Dems can get those back even in a good year at this point with Fitz and now that PA-10 is more GOP and Perry won more than Trump in 2020.

You forgot the most important change, R's lose an entire seat yet 3/4 Dem swing seats get shored up.

Right, but the GOP should lose a seat. They have the most population loss and they lost the state in 2020.

That was always agreed upon since the begining of this cycle. The Democratic seats still needed to pick up 300k in population of blood red territory. Considering 3/4 swing seats for Democrats got shored up despite that, that's a swell courtmander they got.

https://davesredistricting.org/maps#viewmap::48bc041f-ff25-42bc-a74d-d90f325dde0e

Look at Palandios map. Democrats gain like 14 points from PA17 moving it from somewhere around Trump +8 to Biden +6. They gain like 10 points for PA06 with the tri chop of Berks to drown it out with Montgomery and Chester. . That's a whole 25 points worth gained in swing districts .

It's a neutral map in wbrock67's alternate reality where Biden actually won PA by 9.

Huh? What the f**k are you actually talking about? Biden won Pennsylvania. It's a 9-8 Biden map. Biden won PA slightly. The map has a slight Biden won edge. How is that objectionable? This is literally what a fair map looks like. If Trump won PA slightly, then you'd expect it to be a 9-8 Trump map. How are people actually having an issue with this?!

Because the map was explicitly drawn to help Democrats and explicitly chosen to help Democrats.

If you determine a fair map solely on partisanship then it could be considered fair, but the conventional definition of a fair map is one that is not drawn to maximize a certain political party, which is what this one does.

The map isn't terrible outside of PA-17. There is no VRA seat in Pittsburgh, but keeping the more diverse eastern suburbs with the city is the fair choice, not cleaving them to make PA-17 more democratic. There should be a seat entirely inside Allegheny and that seat should have Pittsburgh. Such a seat already exists, but the PA Court decided that such a setup was not beneficial enough for Democrats.