Congressional Districts - 2016 ACS estimates.

[Oryxslayer]

With 5 of 18 IL CDs on jimrtex's list of the undersized, it's pretty clear why IL must lose at least one CD. The 5 include two minority CDs from Chicago, two CDs from outside Chicagoland, and 1 that skirts the exurbs into downstate. Three are solid D and two are R, but the R seats are at opposite ends of the state. If the loss is only one CD, as currently forecast, I can imagine wholesale changes as the Dems try to maintain the same representation for Chicago and force the loss on the Pubs.

If Dems have full control over redistricting, which requires Rauner to go or Madigan to gain a greater legislative control, I have always assumed the loss would be 12/13. With the 12th shrinking, it perfect sense for the Dems to cut one, and then combine the most Democratic bits to try to create another democratic seat. Some bits might be needed for 17th, but with Chicagoland marching leftward, it might just be easier to go grab some of the suburbs.

[Oryxslayer]

New York

1 New York          0.972
2 New York          0.963
3 New York          1.003
4 New York          0.983
5 New York          1.136
6 New York          1.049
7 New York          1.070
8 New York          1.087
9 New York          1.016
10 New York         0.952
11 New York         1.009
12 New York         0.966
13 New York         1.176
14 New York         0.914
15 New York         1.081
16 New York         1.012
17 New York         1.028
18 New York         0.981
19 New York         0.928
20 New York         0.983
21 New York         0.958
22 New York         0.940
23 New York         0.940
24 New York         0.948
25 New York         0.978
26 New York         0.952
27 New York         0.976

With these numbers, its obvious Upstate will have to take the hit. The obvious district to cut is the 22nd, since it lacks a geographic base and is instead squished between those that do. It getting cut however probaby means a general resuffling upstate that will lock down most seats: Ithica to the 24th, Binghamton to the 23th, Rome/utica to 21st, etc.

[Oryxslayer]

Why on earth have I thought all this time that Berks was in the UCC? 

Because there is a small yet significant exurban region in the south of the country - in don't know.

I always find all this talk about UCCs and macrochops to be rather funny since deep down, you just know the parties will throw the idea of a good map in the garbage and create something squiggley.