Pennsylvania is slated to lose a congressional district at the next census, so there will have to be a new map just two cycles after the state Supreme Court gave us one. Using
these population estimates, I have been trying to see what the implications would be if the new map ends up keeping features of the old map. DRA crashed before I could delve into Pennsyltucky, but I could get a gist of what the electoral implications would be.
The Bucks district (old PA-8, new PA-1) is going to have to expand more into Montgomery County to maintain population. I suppose one could make this district slightly more Democratic by having it snake into the immediate Philadelphia suburbs, but that does not seem as compact is simply taking most of the immediate territory across the county line, pretty much maintaining its current partisan lean.
The Philadelphia districts (old PA-1 and PA-2, new PA-2 and PA-3) will have to take up slightly more of the city, reducing the share of represented by the Delaware district (old PA-7, new PA-5).
As a result, the Delaware district will also have to bite into Montgomery country. I had it expanding all the way to King-of-Prussia, and it remains a safely Democratic district.
Here is where things get a bit interesting. The new Montgomery district (new PA-4) will have to compensate for losses of territory by expanding to take most of Berks county. Assuming that the current Chester+Reading configuration stays for PA-6 (and given Chester's growth, that district will not have to change significantly), that is a lot of Atlas blue territory being added to a previously safe Dem district losing Atlas red territory to Delaware and Bucks. I had it becoming D+4, potentially competitive.
In the projection, those six counties can make exactly six congressional districts.
The Lehigh Valley district (old PA-15, new PA-7) will have to take up about half of Monroe County to maintain population. DRA had this district at R+1, which may be a hair more Republican than the current configuration.
Between the loss of half of Monroe and the overall depopulation of Northeast Pennsylvania, the Scranton/Wilkes-Barre district (old PA-17, new PA-8) will have to take up Carbon County and almost all of Luzerne County. Although this area is very elastic in the age of Trump, these changes would intuitively make the district slightly more Atlas blue.
Between losing Berks, Luzerne, and Carbon, the new PA-9 has lost about half of its population; it would seem a natural candidate to be eliminated altogether. Giving Schuylkill and Lebanon to the Harrisburg district (old PA-4, new PA-10) and the rest to Marino's current district (old PA-10, new PA-12) does not seem like the worst idea. I did not get the chance to see the changes on the map, but I think the Harrisburg district will have to lose significant territory in Cumberland and/or York to maintain population equity. I imaging this makes the Harrisburg district safer for Perry or any Republican representing the district in four years; although who knows if Tim Holden has staying power after a decade out of Congress?
The Lancaster district (old PA-16, new PA-11) has been growing rapidly and can remain largely as is. The question is would Wolf veto a map that included York in this district rather than the Harrisburg district?
After this I skipped the remaining districts and went straight to the Pittsburgh metro area. For the Pittsburgh proper district (old PA-14, new PA-18) I thought the Allegheny River was the most coherent northern boundary, and I simply added towns clockwise through Allegheny County until reaching the desired population. This remains safely Democratic of course.
The Northern Allegheny district (old PA-12, new PA-17) will have to take about half of Butler County to maintain population, making it slightly more Republican than the current configuration. I have it at R+4, although maybe a different choice of Pittsburgh suburbs would yield a different result.
I did not map out the SWPA district (old PA-18, new PA-14), but it looks like to maintain population it will have to take up all of Westmoreland County and part of Somerset County. This will presumably maintain population equity for Shuster's old district (old PA-9, new PA-13) after it absorbs most of Cumberland county.
I did not really look at the remaining districts, but they will presumably all remain solidly Republican.