2020 Redistricting in Pennsylvania

[dpmapper]

Here's what I'd do with eastern PA if I was trying go solely by clean lines and CoI:



The 6-county Philly metro is just shy of 6 districts.  Two Philadelphia districts.  Bucks County gets a strip of MontCo, per tradition.  Two other inner suburban districts based in Delaware and MontCo, respectively.  Berks is kept whole and paired with exurban Chester, a very natural match.  This seems the most sensible way of dividing the region into 6 pieces, and then we add a few thousand from Lancaster.  

Two more districts in the south-central, you can divide this however you like but they'll both be pretty safely GOP if the lines are clean.  Lehigh Valley is kept whole again, and Carbon is a natural fit along with a piece of Monroe.  The 9th and the 12th are fused, you can jiggle the lines in Luzerne to put Meuser in this district to go head to head vs Keller if you want.  

Partisan result: GOP loses one district but 6th, 7th, 8th, 10th all move rightward.  As noted above, all of them are pretty much guaranteed to do so under any fair map.  

[dpmapper]

Your east is very similar to what I posted here:

https://talkelections.org/FORUM/index.php?topic=353932.msg7125474#msg7125474

I don't think Lebanon should be attached to the rural north, though.  It belongs with either Dauphin or Lancaster.  You can detach the western end of Cumberland and put that with the 13th. 

I also don't like the 16th crossing the Allegheny River northeast of Pittsburgh.  That seems like a natural border that you don't need to break multiple times.  The 17th can take all of Pittsburgh, everything in Allegheny County between the Allegheny and the Monongahela, plus whatever else is necessary to make population. 

[dpmapper]

I'm going by cleanest lines and COIs, not trying to engineer any outcomes (unlike the PA supremes who made the current map).  To me, the rivers in Allegheny give the most natural dividers; that's all there is to it.  Let the chips fall where they may. 

Lebanon is clearly more connected to Lancaster and Dauphin than it is to Lycoming etc., so if you're just going by COI and not trying to put a finger on the scale for Dems, that's where it should go.  I don't know what you mean by a "rational arrangement" with York; it worked pretty well in my map. 

Cumberland+Dauphin+York+Lancaster is not going to end up being exactly 2 districts, so you're going to have that extra county split once the final numbers come in anyway. 

[dpmapper]

Why would the 17th go into Lawrence and Mercer counties before taking parts of Butler?  That doesn't make any COI sense. 

I'd also try to get eastern Cumberland County into 10/11 rather than Adams.  It definitely fits better with the York/Lancaster/Harrisburg area than with the counties to the west. 

[dpmapper]

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

I actually think this map is pretty decent! The only nitpicks I'd have are:
1. I don't think the cut in Somerset is necessary--if you send the 12th deeper into Butler you can keep more of the Pittsburgh area in Pittsburgh districts, and do a cut somewhere between 15 and 13.
2. Luzerne-Lackawanna-Pike-Monroe is exactly the size of 1 district, and it's a decent CoI. Carbon is a better fit with the Lehigh Valley district than with Scranton.

I agree, but would add that Schuylkill doesn't fit so well with Harrisburg/York/Lancaster, and would be better appended to your 10th so that the 9th and 11th can take more of Cumberland/York counties. 

[dpmapper]

Here's my latest version.  I particularly like the south central districts, which together are able to squeeze in as much of the Harrisburg/York/Lancaster-based areas as possible (northern Dauphin is extremely rural and I'd rather get more of Cumberland than that part of Dauphin), and the fact that the light green in the north/northeast is pretty coherent as a COI and quite compact as well. 

[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. 

[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.)