2020 Redistricting in Pennsylvania

[Sol]

Also, is Baltimore sprawl up in PA at this point? Oy vey.

[Starry Eyed Jagaloon]

Also, is Baltimore sprawl up in PA at this point? Oy vey.

Not really. I think there are some supercommuters from York County but it's still rural.

[Boss_Rahm]

Here's my proposal for Pennsylvania, which I think has a lot going for it:
- There are just 12 (!) county chops, but the population deviations are all less than +/- 1,000
- Greater Pittsburgh keeps 3 whole districts
- Exurban Baltimore gets its own district
- There's continuity in the suburban Philadelphia districts, with compactness arguably improving
- Both Philadelphia districts are 60% minority and 40% Black
- Carbon County joins the Lehigh Valley district
DRA link: https://davesredistricting.org/join/3108f1e7-7e09-49bd-83f8-4ecdd85acfd6

Not bad at all, though I don't love separating Cumberland and Dauphin.

Me neither, though honestly I've yet to see a SCPA configuration that I like. For this map I started with the York-Adams district and drew from there. From what I've heard the rapid growth in those counties is due to proximity to Baltimore.

[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.

[Sol]

Splitting Pittsburgh is a dummymander.

[Torie]

FYI you can easily nest two districts in Dauphin, York, Cumberland, and Lancaster.

I saw that, but if Berks goes with the Philly metro, then there's the unfortunate connection of Lebanon to Schuylkill to points north. It looked even worse in terms of compactness than the CD 9 on my map, so I dropped the idea.

Why is putting Lebanon and Schuykill in the same CD a thought crime?

[dpmapper]

Geographically (in the lowlands south of Blue Mountain) and culturally (very German) it is a natural cousin to Lancaster County and is quite an awkward fit with the upland coal regions to the northeast.  Better to have Lebanon + Lancaster + Dauphin + York + east Cumberland as the two south-central districts, ceding western Cumberland to a central PA district. 

[Torie]

Geographically (in the lowlands south of Blue Mountain) and culturally (very German) it is a natural cousin to Lancaster County and is quite an awkward fit with the upland coal regions to the northeast.  Better to have Lebanon + Lancaster + Dauphin + York + east Cumberland as the two south-central districts, ceding western Cumberland to a central PA district. 

These maps have a very similar design, which is not surprising since the authors tend to hew to very similar metrics. Which do you like better? For me, lack of compactness though trumps perceived COI's. I guess assuming the chop situation is not exacerbated unduly that I give more weight to compactness than most (Muon2 characterizes it as the "artist syndrome" in me, which although not meant as a compliment, I take as one  ) The district that runs from Pike to Schuylkill (man that county is hard to spell for me), drives me nuts. The space in which the S county is wedged between just begs to be absorbed by the Harrisburg based CD. I do think the tri-chop of Allegheny might be superior however. I tend to dislike tri-chops, but accept them if the payoff is sufficient.

[Sol]

That second map looks better to me, though I don't love the split of York.

[dpmapper]

I don't like the split of York in either version, but I'd take the first one over the second. 

I posted this map back a month or so ago, which I think is pretty close to ideal outside the Philadelphia-area districts.  (The fact that Lackawanna + Luzerne + Monroe + Pike is supposedly one exact district population-wise doesn't matter to me, since it isn't going to be exact when the final population numbers come out.)

[Torie]

I think you persuaded me, outside of SEPA, where I like my choices.

As a caveat, sure the final population will almost certainly not be within one precinct of "perfect," but the issue that drives this preference is not that, but rather whether it is still a very small discrepancy - small enough that it would be legal under the US  Constitution as now interpreted to tolerate such degree of  discrepancy, at least in order to effect  a good end, e.g., in order to avoid a county or municipal chop. That degree of discrepancy figure at the moment is within 1% for CD's. So basically, for this round, no CD can be more than 0.5% from the "perfect" number, or within a bit less than 4,000 persons from the absolute parity number.

You probably know all of this already.

[palandio]

I was skeptical about Luzerne+Lackawanna+Monroe+Pike being exactly one district in 2020, but according to 2019 estimates they're really only ca. 100 inhabitants away from the perfect quota, so it's quite likely that this will be similar in 2020.

[Torie]

Due to the most excellent crowd sourcing, this is my synthesis.

[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.

[RussFeingoldWasRobbed]

if Fitzpatrick gets shored up I'm going to be pissed. Considering he's going to run for senate in either 2022 or 2024, his seat will most definitely flip to us in anything similar to it's current form.

[palandio]

[...]

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.

[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.

[palandio]

[...]

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.

Yes, no doubt that under compactness considerations* and non-splitting considerations your arrangement or something very similar makes the most sense.

If you wanted to draw a Lamb seat under 2016 numbers that is as Dem-friendly as possible and still leaves a Pittsburgh seat entirely contained in Allegheny, you would put the South and East of Allegheny into Lamb's seat and the North and West into the Pittsburgh seat. Adding Washington and parts of Westmoreland would even give you a Clinton seat, although with less favorable trends than Lamb's current seat. The ugliness of this arrangement would mostly come from ripping the Washington-Greene-Fayette-Westmoreland area apart.

* My personal definition of compactness for districts differs slightly from the most common ones: Voters with a small geographic distance between them should be in the same district. E.g. for every two voters that are in the same district, the map gets a score that is proportional to e.g. minus the logarithmized geographic distance of these voters. Bonus score if the voters live in the same county and the same city. Neat borders and good shapes are the automatic products of this criterion, but they are not the criterion itself.

[President Punxsutawney Phil]

[...]

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.

Yes, no doubt that under compactness considerations* and non-splitting considerations your arrangement or something very similar makes the most sense.

If you wanted to draw a Lamb seat under 2016 numbers that is as Dem-friendly as possible and still leaves a Pittsburgh seat entirely contained in Allegheny, you would put the South and East of Allegheny into Lamb's seat and the North and West into the Pittsburgh seat. Adding Washington and parts of Westmoreland would even give you a Clinton seat, although with less favorable trends than Lamb's current seat. The ugliness of this arrangement would mostly come from ripping the Washington-Greene-Fayette-Westmoreland area apart.

* My personal definition of compactness for districts differs slightly from the most common ones: Voters with a small geographic distance between them should be in the same district. E.g. for every two voters that are in the same district, the map gets a score that is proportional to e.g. minus the logarithmized geographic distance of these voters. Bonus score if the voters live in the same county and the same city. Neat borders and good shapes are the automatic products of this criterion, but they are not the criterion itself.

So, say you draw a district covering Somerset, Washington, Greene, Fayette, and as much of Westmoreland as possible, this would help Lamb?

[palandio]

[...]

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.

Yes, no doubt that under compactness considerations* and non-splitting considerations your arrangement or something very similar makes the most sense.

If you wanted to draw a Lamb seat under 2016 numbers that is as Dem-friendly as possible and still leaves a Pittsburgh seat entirely contained in Allegheny, you would put the South and East of Allegheny into Lamb's seat and the North and West into the Pittsburgh seat. Adding Washington and parts of Westmoreland would even give you a Clinton seat, although with less favorable trends than Lamb's current seat. The ugliness of this arrangement would mostly come from ripping the Washington-Greene-Fayette-Westmoreland area apart.

* My personal definition of compactness for districts differs slightly from the most common ones: Voters with a small geographic distance between them should be in the same district. E.g. for every two voters that are in the same district, the map gets a score that is proportional to e.g. minus the logarithmized geographic distance of these voters. Bonus score if the voters live in the same county and the same city. Neat borders and good shapes are the automatic products of this criterion, but they are not the criterion itself.

So, say you draw a district covering Somerset, Washington, Greene, Fayette, and as much of Westmoreland as possible, this would help Lamb?

If the rest of Westmoreland is used to fill up the population deficit of the Pittsburgh district, then yes, of course would this help Lamb. Because otherwise, as kwabbit said, the Pittsburgh district would need to take in some of the most Dem-friendly areas from Lamb's seat.

[Boss_Rahm]

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.

[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.

[Boss_Rahm]

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.

[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?

[lfromnj]

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?

Its pretty heavily inferred based on the D friendly decisions made in Bucks(pretty defendable, as it has to take some slice of either Montgomery or Philly but shows intent, ) and PA 17th which scoops both Penn Hills and Mt.Lebanon with the double pincer arms in PA 17th which also makes PA 18th wrap around those arms.Also PA 10th a bit as a last swing district towards D's.