2020 Redistricting in Pennsylvania

[President Punxsutawney Phil]

What is the population of Montgomery minus the part south of the Schuylkill?

722,889

Tbh, I could see a map where Bucks draws the entirety of the leftovers from Philly, then you have a Philly seat that takes in those leftovers from MontCo and whatever needed from DelCo, and then a CD is drawn from DelCo+Chester.

[President Punxsutawney Phil]

What is the population of Montgomery minus the part south of the Schuylkill?

722,889

Tbh, I could see a map where Bucks draws the entirety of the leftovers from Philly, then you have a Philly seat that takes in those leftovers from MontCo and whatever needed from DelCo, and then a CD is drawn from DelCo+Chester.

Thoughts?

Interesting arrangement. I do like the compactness and synergy of 2 Philly-centric seats and 3 inner-ring ones all bordering it.
Delaware being split is a shame but it's better than the alternative - the screenshot you posted is highly illuminating.
If we have to have 4 seats taking from Philly and all the SEPA counties except Bucks split in some way, this is among the very best ways of doing it.

[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?

[President Punxsutawney Phil]

Two questions:

1) Why do folks seem to be assuming that Lamb's district won't be made more Democratic by giving it some more Democratic territory in Allegheny County while adding some more Republican turf (ex: taking parts of northern Alleghany County and/or some of southern Butler County) to Doyle's district?  I mean, yes, that'd be something you'd see in a Democratic map, but it's not so unreasonable that it'd be likely to give pause Democratic-leaning court.  I'd argue this is more likely than Lamb's district gaining southern Butler County (assuming it doesn't cause too many issues elsewhere in the map).  When in doubt, the PA SC's map is gonna favor the Democrats and this seems like a perfect example of somewhere that could happen.

2) Does anyone know why the "don't split Bucks County" rule has persisted for so long?  I'm not saying I expect it to change; I'm just curious.

Wouldn't it be more efficient to give Lamb all the Dem turf directly east of Pittsburgh, remove Butler, and turn his district into a Beaver+all of Allegheny as needed, and then give Doyle parts of Washington County instead?

[President Punxsutawney Phil]

Two questions:

1) Why do folks seem to be assuming that Lamb's district won't be made more Democratic by giving it some more Democratic territory in Allegheny County while adding some more Republican turf (ex: taking parts of northern Alleghany County and/or some of southern Butler County) to Doyle's district?  I mean, yes, that'd be something you'd see in a Democratic map, but it's not so unreasonable that it'd be likely to give pause Democratic-leaning court.  I'd argue this is more likely than Lamb's district gaining southern Butler County (assuming it doesn't cause too many issues elsewhere in the map).  When in doubt, the PA SC's map is gonna favor the Democrats and this seems like a perfect example of somewhere that could happen.

2) Does anyone know why the "don't split Bucks County" rule has persisted for so long?  I'm not saying I expect it to change; I'm just curious.

Wouldn't it be more efficient to give Lamb all the Dem turf directly east of Pittsburgh, remove Butler, and turn his district into a Beaver+all of Allegheny as needed, and then give Doyle parts of Washington County instead?

That’d also work and just underscores my point about how easy it is to shore up Lamb.

https://davesredistricting.org/join/f3410140-478f-48b0-ba35-e8acd88c5f2b
thoughts on this map?

[President Punxsutawney Phil]

With the recent chatter about Madeleine Dean running for Senate, it might be a good opportunity to look at maps which use her territory to make Houalahan more safe.

Might we see MontCo split up among 3-4 districts?

[President Punxsutawney Phil]

Former University of Pittsburgh chancellor named the tiebreaker vote for the PA state legislative maps.

https://twitter.com/SamDunklau/status/1389303502137081858?s=20

So does this mean we get a map in the same spirit as the previous one?

[President Punxsutawney Phil]

Anyone else drawing state House maps?

[President Punxsutawney Phil]

Anyone else drawing state House maps?

Here's a map I drew tabula rasa, aiming for compactness and respecting county lines.
https://davesredistricting.org/join/022ab1b1-f183-40bf-b748-f1d71e8d7928

Here's one I have, WIP
https://davesredistricting.org/join/dcecec00-9d0a-48d0-a81b-4bb83522205d

[President Punxsutawney Phil]

Does anyone think if the Dems win the Supreme Court race and get 6-1 that they can maybe convince the court to draw a 11-6 map? I feel like the Dems will be bold in asking considering what will happen in states like FL.

The court-drawn congressional map (if there is one) will probably be Dem favorable, but it also definitely not going to be 11-6.

[President Punxsutawney Phil]

PA State Senate map I made.
Rules:
1) county splits should be avoided as much as is reasonable, with the 10% deviation band being used to full effect if need be.
2) municipal splits are verboten unless the municipality has too many people for one district, in which case only one district can cross out of its borders.
3) effort would be taken to avoid packing minorities.
4) compactness is quite important.
5) urban municipalities are generally to be paired with nearby suburbs.

In Philly and Pittsburgh:
Districts should try to follow Broad Street and/or rivers
No ward splits in Philly
Baldwin had to go in a Pittsburgh district for compactness reasons
Some effort should be taken to draw a Latino influence seat in Philly and Black influence seat in Alleghany County

There are 23 Clinton districts, 26 Casey '18 districts, and 35 Wolf '18 districts. There are likely to be 28 Biden districts. In the 2012-2018 Composite, there are 27 districts voting Dem.
https://davesredistricting.org/join/a7458821-f52f-46ed-9c4c-fe3f6a58e883

[President Punxsutawney Phil]

https://davesredistricting.org/join/222b5cee-1ab5-472a-8ea0-53ea1eb85515

I’m not sure cracking Pittsburgh is a good idea. Those districts are like Biden+11 and Biden+14 and may fall in a wave. Better to have a safe seat and a swing or even R-leaning seat.

That doesn't follow what we've seen in states like Nevada or Oregon.   Democrats seem more interested in maxing their ceiling than their floor.

Don’t forget Illinois.

We also may be seeing the same pattern in MD, NJ, NY if Dems get too greedy.

If Dems are losing Biden + 8 districts, the House is already long gone and so is the Senate of course.

If Biden+11 isn't "safe" then I shudder to imagine what the baseline is for a "safe seat" even is.
Biden+11 and Biden+14 is an unalloyed good for Democrats. 100 times out of a 100.

[President Punxsutawney Phil]

I am once again asking people to recognize that with both Lamb and Doyle out, there is no longer any need to preserve the ugly current PA-17 Pittsburgh reach-around. Just grab all of the Penn hills region to the west of the city and use the rivers as guidelines for district borders. This near-guarantees a Biden seat, one that could even be more Democratic than the nation if you know what you are aiming for.

Problem is Rs controlling the state legislature would have a collective stroke if Allegheny is drawn too unfavorably to them.

We know the map is either going to the D courts or end up a D-favoring compromise (that'll leave their seats intact and favorable) because the D's used said court as leverage and got a map they liked, so why do they matter? In the latter scenario the R's would care more about securing their own then spending little capital on offense, and the courts in the former clearly wanted to do it in 2018 except Lamb lived in Mt. Lebanon and Doyle had a base in the Swissvale area.

Didn't they draw the 6D/5 swing/7 R map before the special election Lamb won or am I misremembering? Either way as hard as it is to believe 6D/5 swing/6R is D-leaning considering how f---ed the geography of the state is (inb4 "land doesn't vote!" Sorry, we've already decided property >>>> life in this country.) Any more and Rs prolly strip the 5-2 Court of the authority to appoint the tie-breaker to the commission at the first opportunity.

Granted, knowing the um... authoritarian the PAGOP has taken they'll prolly do that anyway whenever they take back the governor's mansion so maybe you're right after all.

The commission is only for legislative lines. Congressional districts are a bill that (likely will not) pass the chamber and the governor's pen, which is why an outside authority will be needed - the same court as last time. And said court last time took steps to correct for the state's geographic lean, which means a mild D-favoring map.

TBH I don't like 'corrective mapping' like this in fair Congressional lines, cause various statewide geographic advantages and the VRA work to cancel out any real political benefit nationwide, so one does not need to correct in a single state. But that is not the rules we play by, and that is not the rules the PA court recognized in 2018. 

https://davesredistricting.org/join/e9498594-cb08-4a0a-afe8-96e209594042
This is a quick mock-up of a map trying to follow the rules the PA SC has used.
Did I do a good job?

[President Punxsutawney Phil]

also just wondering in my map there’s two minority majority seats in Philly, what do y’all think? Is it likely to happen?

I suppose it could quite likely happen. Especially if the map drawers last time are doing it this time as well.

[President Punxsutawney Phil]

I am once again asking people to recognize that with both Lamb and Doyle out, there is no longer any need to preserve the ugly current PA-17 Pittsburgh reach-around. Just grab all of the Penn hills region to the west of the city and use the rivers as guidelines for district borders. This near-guarantees a Biden seat, one that could even be more Democratic than the nation if you know what you are aiming for.

Problem is Rs controlling the state legislature would have a collective stroke if Allegheny is drawn too unfavorably to them.

We know the map is either going to the D courts or end up a D-favoring compromise (that'll leave their seats intact and favorable) because the D's used said court as leverage and got a map they liked, so why do they matter? In the latter scenario the R's would care more about securing their own then spending little capital on offense, and the courts in the former clearly wanted to do it in 2018 except Lamb lived in Mt. Lebanon and Doyle had a base in the Swissvale area.

Didn't they draw the 6D/5 swing/7 R map before the special election Lamb won or am I misremembering? Either way as hard as it is to believe 6D/5 swing/6R is D-leaning considering how f---ed the geography of the state is (inb4 "land doesn't vote!" Sorry, we've already decided property >>>> life in this country.) Any more and Rs prolly strip the 5-2 Court of the authority to appoint the tie-breaker to the commission at the first opportunity.

Granted, knowing the um... authoritarian the PAGOP has taken they'll prolly do that anyway whenever they take back the governor's mansion so maybe you're right after all.

The commission is only for legislative lines. Congressional districts are a bill that (likely will not) pass the chamber and the governor's pen, which is why an outside authority will be needed - the same court as last time. And said court last time took steps to correct for the state's geographic lean, which means a mild D-favoring map.

TBH I don't like 'corrective mapping' like this in fair Congressional lines, cause various statewide geographic advantages and the VRA work to cancel out any real political benefit nationwide, so one does not need to correct in a single state. But that is not the rules we play by, and that is not the rules the PA court recognized in 2018.  

https://davesredistricting.org/join/e9498594-cb08-4a0a-afe8-96e209594042
This is a quick mock-up of a map trying to follow the rules the PA SC has used.
Did I do a good job?

I think you did a good job, and made reasonable choices assuming a Dem friendly but not hackish court that will follow a least change approach in general to the map they drew last time. My main issue is the exchange of real estate between the two CD's in Allegheny County. I understand that makes the Lamb seat more Dem, but aside from that, what is the justification for the exchange that would be based on neutral redistricting metrics?

The goal was to keep it very competitive. The seat is expanding north into very R territory anyway, so giving it those parts of Allegheny County is a way to maintain its partisanship.
This of course is important for proportionality, which is part of what the court's criteria is. But it's defendable more generally on neutral grounds as well, as helping maintain a competitive district.

[President Punxsutawney Phil]

I am once again asking people to recognize that with both Lamb and Doyle out, there is no longer any need to preserve the ugly current PA-17 Pittsburgh reach-around. Just grab all of the Penn hills region to the west of the city and use the rivers as guidelines for district borders. This near-guarantees a Biden seat, one that could even be more Democratic than the nation if you know what you are aiming for.

Problem is Rs controlling the state legislature would have a collective stroke if Allegheny is drawn too unfavorably to them.

We know the map is either going to the D courts or end up a D-favoring compromise (that'll leave their seats intact and favorable) because the D's used said court as leverage and got a map they liked, so why do they matter? In the latter scenario the R's would care more about securing their own then spending little capital on offense, and the courts in the former clearly wanted to do it in 2018 except Lamb lived in Mt. Lebanon and Doyle had a base in the Swissvale area.

Didn't they draw the 6D/5 swing/7 R map before the special election Lamb won or am I misremembering? Either way as hard as it is to believe 6D/5 swing/6R is D-leaning considering how f---ed the geography of the state is (inb4 "land doesn't vote!" Sorry, we've already decided property >>>> life in this country.) Any more and Rs prolly strip the 5-2 Court of the authority to appoint the tie-breaker to the commission at the first opportunity.

Granted, knowing the um... authoritarian the PAGOP has taken they'll prolly do that anyway whenever they take back the governor's mansion so maybe you're right after all.

The commission is only for legislative lines. Congressional districts are a bill that (likely will not) pass the chamber and the governor's pen, which is why an outside authority will be needed - the same court as last time. And said court last time took steps to correct for the state's geographic lean, which means a mild D-favoring map.

TBH I don't like 'corrective mapping' like this in fair Congressional lines, cause various statewide geographic advantages and the VRA work to cancel out any real political benefit nationwide, so one does not need to correct in a single state. But that is not the rules we play by, and that is not the rules the PA court recognized in 2018.  

https://davesredistricting.org/join/e9498594-cb08-4a0a-afe8-96e209594042
This is a quick mock-up of a map trying to follow the rules the PA SC has used.
Did I do a good job?

I think you did a good job, and made reasonable choices assuming a Dem friendly but not hackish court that will follow a least change approach in general to the map they drew last time. My main issue is the exchange of real estate between the two CD's in Allegheny County. I understand that makes the Lamb seat more Dem, but aside from that, what is the justification for the exchange that would be based on neutral redistricting metrics?

The goal was to keep it very competitive. The seat is expanding north into very R territory anyway, so giving it those parts of Allegheny County is a way to maintain its partisanship.
This of course is important for proportionality, which is part of what the court's criteria is. But it's defendable more generally on neutral grounds as well, as helping maintain a competitive district.

Are you sure that making seats competitive or proportionality was explicitly embraced by the court? In addition, the existing map has an ugly chop of the black community, creating an erose line to boot. What I did in the map below, is have the Pittsburgh seat take the balance of the two chopped cities, and then smooth out the line south of the river, and then take one small city in the other indented area to the south, and then chop a small city by about 300 people. The Lamb CD is still quite competitive. I would be surprised if the court goes for erosity and chopping the black community to make the seat a couple of points more Dem.

https://davesredistricting.org/join/0aba5052-7f1f-4d91-a9d7-399abe34d796

Proportionality was definitely a factor, albeit only one factor, in how the PA SC drew the lines last time (just look at how the Bucks County CD was drawn).
It'd be surprising if a court were to place having as much of the blacks of Allegheny County in one seat above all considerations either. The existing court map has Penn Hills (37% AA) in the northern Allegheny seat. Let's not forget this is a county that is only 13% black. If it were, say, double that, then there might be a case. In any case, to the extent that it would be even relevant, it's probably likely that if given a choice, AAs in the county would prefer to be divided for sake of improving D chances in the swing district, as opposed to packing Ds into one safe seat.

[President Punxsutawney Phil]

That map looks mildly GOP-friendly.

[President Punxsutawney Phil]

Did Ryan Costello draw this map?

Even if he didn't, it'd look like he did.

[President Punxsutawney Phil]

Did Ryan Costello draw this map?

Even if he didn't, it'd look like he did.

Nope, PA06 is actually *slightly Dem friendly at a microlevel because PA05 takes in West Chester county. PA06 going into Lebanon doesn't really matter because most other maps would have it taking in similarly red areas in Berks instead.

PA-06 under these lines still sort of resembles his seat back in the old GOPmander from the early 2010s though.

[President Punxsutawney Phil]

I just don't think Susan Wild would accept this map. Maybe make PA-08 redder and 7 like Biden +9 or something. Then make Houlahan's a little redder but still solid D. That would make sense.

Cartwright has more seniority and has more state house reps backing him. Not sure what Yudichak prefers. He caucuses with the GOP in a pretty red presidential senate seat although he still endorsed Biden last year.

I just don't think Susan Wild would accept this map. Maybe make PA-08 redder and 7 like Biden +9 or something. Then make Houlahan's a little redder but still solid D. That would make sense.

Cartwright has more seniority and has more state house reps backing him. Not sure what Yudichak prefers. He caucuses with the GOP in a pretty red presidential senate seat although he still endorsed Biden last year.

Well again they could take the most D areas from Pennsylvania 7 and 8 and have those two fight it out. Im not sure if there is a way to give Cartwright an advantage in that primary, but that's something I could see happening.

https://davesredistricting.org/join/5a26f42a-b2b6-4505-a766-778e33816e76
Does this look like a possible arrangement in NE PA+Lehigh Valley?

[President Punxsutawney Phil]

I just don't think Susan Wild would accept this map. Maybe make PA-08 redder and 7 like Biden +9 or something. Then make Houlahan's a little redder but still solid D. That would make sense.

Cartwright has more seniority and has more state house reps backing him. Not sure what Yudichak prefers. He caucuses with the GOP in a pretty red presidential senate seat although he still endorsed Biden last year.

I just don't think Susan Wild would accept this map. Maybe make PA-08 redder and 7 like Biden +9 or something. Then make Houlahan's a little redder but still solid D. That would make sense.

Cartwright has more seniority and has more state house reps backing him. Not sure what Yudichak prefers. He caucuses with the GOP in a pretty red presidential senate seat although he still endorsed Biden last year.

Well again they could take the most D areas from Pennsylvania 7 and 8 and have those two fight it out. Im not sure if there is a way to give Cartwright an advantage in that primary, but that's something I could see happening.

https://davesredistricting.org/join/5a26f42a-b2b6-4505-a766-778e33816e76
Does this look like a possible arrangement in NE PA+Lehigh Valley?

I mean that's more or less what they did except switch Hamilton for Smithfield . Basically my guess is if there is a compromise map the GOP will allow Democrats to choose whichever for the 2 districts as one of them has to move right and the other stays stagnant.

That makes sense.

[President Punxsutawney Phil]

Wish there was a more Harrisburg centered district but not a bad map.

It's fairly easy to make a pretty Safe R Harrisburg district which would just mostly be Cumberland + Dauphin + Lebanon + 50k random pop. The issue however is Lancaster County is the base of the PA GOP and the house redistricting chair is from York. SCPA is basically 2 districts worth of pop so even without partisan implications Harrisburg would be the one to get chopped by any GOP map especially considering Perry is from York and Smucker is from Lancaster.

The most gerrymandered part is keeping the Lackawanna/Lehigh configuration where they make PA07 and PA08 both more red by having PA08 taking in random rurals before taking in the rest of the Wilkes Barres area.

Also they made PA06 more R but also more compact as I said earlier where even though it seemed that PA06 was a R gerrymander in Holton's map it was relatively D friendly.

A thought: why couldn't  Harrisburg be paired with State College in a fair-fight district, while Smucker and Perry both get the sort of districts they want?

[President Punxsutawney Phil]

Wish there was a more Harrisburg centered district but not a bad map.

It's fairly easy to make a pretty Safe R Harrisburg district which would just mostly be Cumberland + Dauphin + Lebanon + 50k random pop. The issue however is Lancaster County is the base of the PA GOP and the house redistricting chair is from York. SCPA is basically 2 districts worth of pop so even without partisan implications Harrisburg would be the one to get chopped by any GOP map especially considering Perry is from York and Smucker is from Lancaster.

The most gerrymandered part is keeping the Lackawanna/Lehigh configuration where they make PA07 and PA08 both more red by having PA08 taking in random rurals before taking in the rest of the Wilkes Barres area.

Also they made PA06 more R but also more compact as I said earlier where even though it seemed that PA06 was a R gerrymander in Holton's map it was relatively D friendly.

A thought: why couldn't  Harrisburg be paired with State College in a fair-fight district, while Smucker and Perry both get the sort of districts they want?

I was working on that but anyway compromise map just nukes it or atleast keeps it Trump +10 as its the last thing Dems will want. They only have 3 state reps in the entirety of the state college, Harrisburg and York area. No state senators either so little push for it.

Ah, that makes sense.
Ds pushing for a fair-fight Dauphin-to-Penn State CD would likely come at the expense of one of their SEPA incumbents too, come to think about it. Give-and-take is the essence of a bipartisan compromise map.

[President Punxsutawney Phil]

https://davesredistricting.org/join/c011e3b9-9b53-4bc8-9846-8c493d29d378
(An effort at a) bipartisan compromise map that splits no townships. Definitely at least a bit D friendly (especially to Dem incumbents), but the Lehigh CD, the median district, is more R-friendly than its current iteration, in fact, perfectly mirroring the state's partisanship with 2020 numbers, and also has a R+ PVI on 2016/2020 numbers.

[President Punxsutawney Phil]

https://davesredistricting.org/join/c011e3b9-9b53-4bc8-9846-8c493d29d378
(An effort at a) bipartisan compromise map that splits no townships. Definitely at least a bit D friendly (especially to Dem incumbents), but the Lehigh CD, the median district, is more R-friendly than its current iteration, in fact, perfectly mirroring the state's partisanship with 2020 numbers, and also has a R+ PVI on 2016/2020 numbers.

Do Republicans have a shot at either of the Allegheny County districts in 2022 with this map?

Biden won them both by more than a dozen points.