2020 Redistricting in Pennsylvania

[SevenEleven]

D gerrymander Lfromnj keeps asking for.

We should be so lucky, but I doubt the court goes for that Harrisburg district.

Court would never, this is why you gotta win state legislatures.

[SevenEleven]

Made some modest changes to 13, 14, 15, 16 and 17.

Much better IMO. I count the minimum of 16 chops in 13 counties with Allegheny, Berks, and Philadelphia with 2 chops and the rest with 1 chop. That aspect looks good from the criteria. Were you able to keep municipal chops to a minimum, too? I know they aren't always obvious unless you want to read the title of each precinct. May I ask what the biggest deviations were plus and minus from the ideal?

https://davesredistricting.org/join/364fb604-2395-4513-8981-25ff353debed

Also, fun fact: the Scranton is district on my D gerrymander is four whole counties with no cuts or additional precincts, and has exact population. That obviously won't be the case when the real numbers are available, but hey.

[SevenEleven]

What's to make it fair?

[SevenEleven]

The problem is sometimes what is fair as opposed to what is neutral. People tend to think of fair in partisan terms, but that can run up against neutral mapping principles. I use the term skew to measure the lack of partisan fairness in a plan.

Skew in PA comes naturally from the city of Philly, especially with the necessary Black-majority CD. That VRA-mandated CD must be placed almost entirely in the city, and often is completely within the city. In fact, most neutral mapping efforts would put 2 CDs either entirely or mostly in the city for reasons of compactness or community of interest. Any plan that feathered more than 2 Philly CDs into the surrounding counties would smack of gerrymandering. And other than going into Bucks, those Philly CDs would have to feather out quite a ways to dilute the Dem pool in the city.

To show the impact look at the 2012/2016 PVI of the whole state: R+0.38, and without Philly R+4.95. That's a big shift. Moreover consider that the rest of the state would get 15 CDs. At R+5 the usual analysis (50%+ 2*PVI) would lead to the expectation that the Pubs would hold a PVI advantage in 60% of those seats, which is 9. So despite the effectively even statewide number Pubs should hold a 9-8 advantage in most scenarios.

That's basically what my map is, although Lamb and Cartwright could conceivably win their Trump districts, and Fitzpatrick could potentially hold his Bucks Clinton district.

Although "fair" could mean other things, such as adequate minority representation, keeping metro areas whole, etc. Philly metro is essentially six districts +6000 so there's no reason to break it up in my mind.

[SevenEleven]

My first thought is that district 9 kind of feels like a "leftovers" district. I did try some rotation around York and Lancaster to pair Cumberland with Dauphin but overall deemed it unnecessary. I also dislike the double cut into Montgomery, I'm sure it's for optimal population purposes but I blanket ban double cutting from my fair maps.

[SevenEleven]

Since you have been kind enough to let me quiz you on your maps, it's only fair that you get to poke at mine.

This is a very good map. My only quibble is probably the 3-way split of York. I would instead put a bit of northwestern Lancaster County in the 10th district, as that area is more closely tied to Harrisburg than to the city of Lancaster.

My first thought is that district 9 kind of feels like a "leftovers" district. I did try some rotation around York and Lancaster to pair Cumberland with Dauphin but overall deemed it unnecessary. I also dislike the double cut into Montgomery, I'm sure it's for optimal population purposes but I blanket ban double cutting from my fair maps.

That's a tough call that I spent some time thinking about. Initially I had Lebanon with Lancaster which meant the Harrisburg CD picked up the city of York. The number of chops is the same either way. But it was an erose chop into York, and I could be more compact putting both chops in York county. Since compactness matters, too, I went in the direction of the double chop. As far as using part of Lancaster, the Fairview Park/Newberry corner of York is advertised as part of suburban Harrisburg these days, so that was another factor.

I guess my point is that keeping counties together doesn't mean very much if you're picking and choosing from opposite ends (MontCo).

[SevenEleven]

Since you have been kind enough to let me quiz you on your maps, it's only fair that you get to poke at mine.

This is a very good map. My only quibble is probably the 3-way split of York. I would instead put a bit of northwestern Lancaster County in the 10th district, as that area is more closely tied to Harrisburg than to the city of Lancaster.

My first thought is that district 9 kind of feels like a "leftovers" district. I did try some rotation around York and Lancaster to pair Cumberland with Dauphin but overall deemed it unnecessary. I also dislike the double cut into Montgomery, I'm sure it's for optimal population purposes but I blanket ban double cutting from my fair maps.

That's a tough call that I spent some time thinking about. Initially I had Lebanon with Lancaster which meant the Harrisburg CD picked up the city of York. The number of chops is the same either way. But it was an erose chop into York, and I could be more compact putting both chops in York county. Since compactness matters, too, I went in the direction of the double chop. As far as using part of Lancaster, the Fairview Park/Newberry corner of York is advertised as part of suburban Harrisburg these days, so that was another factor.

I guess my point is that keeping counties together doesn't mean very much if you're picking and choosing from opposite ends (MontCo).

I put one district entirely within MontCo. Nesting districts entirely within a county when possible is a big issue with some neutral mapping schemes, though I can be flexible on that. I wasn't going to chop municipal Philly more than necessary, since that creates a potential legal weakness. Given the cluster around Philly, I didn't see a better option that moved the second Montco chop to another county.

What I'm talking about is district 1 cutting into both Northern MontCo and southern MontCo. The county cut should be contiguous.

To a lesser extent, I also would try to make the district 5 MontCo cut to an area bordering both Berks and Chester.

[SevenEleven]

Did a variation of East Anglia Lefty's map that Tim Turner will definitely hate. If you can get over the MontCo and Bucks chops, I actually think it reflects SEPA COIs extremely well. Plus it has two AA VRA districts.

Thanks. I hate it.
This is definitely not a good map in my book. You seem to know me well.
For starters, the border of 5th and the 12th, splits two counties.
The 11th and the 5th has a weird border that could be improved.
The 12th splits counties with almost all of its neighbors.
The 4th is a terrible district even leaving aside the MontCo/Bucks split (which, by itself, is not enough to make a map terrible, but is enough to disqualify it from being good). Its shape is instrumental in having all but one of Chester, Montgomery, Bucks, and Delaware split, places such divergent areas as far NW Philly and far NE Bucks in the same district, and somehow despite all of that, 4 districts take from Philadelphia.
You can't even call this a good effort at a CoI map. It's a poor imitation.

What do you think of my Fair Map?

[SevenEleven]

As a general rule, I'm not a huge fan of pairing Berks and Chester.

Why do you say that? I know Berks is generally more working class or whatever you want to call it, but you have to pair something with Berks. Everyone seems to hate splitting Bucks (despite upper and lower Bucks being vastly different in nature), so splitting Chester is really the only option and Berks makes more sense than Lancaster.