This is a new map of Congress for Pennsylvania, drawn by court adviser Nate Persily. I think it’s a landmark contribution to the understanding of partisan equity, in one of the politically heterogeneous countries in the Union – “Pennsatucky”.
For anyone who has drawn such maps, this particular map is a pleasure to see. It does a great job in compliance. It divides into 13 counties, less than any plan has been made to the court. The only plan to divide fewer counties or cities is the “Compact D gerrymander” that the Princeton Gerrymandering Project posted over the weekend. So in terms of basic compliance, it wins.
But more importantly, this map removes the effects of population categorization. As we have presented over the weekend, according to the Pennsylvania Supreme Court rules can only allow a plan to reach partisan equilibrium, ie a 9 D, 9 R result for a 50-50 statewide vote. However, those rules of bias are more likely in favor of Republicans, so a Republican gerrymander – one of the proposals on the table – is also a possibility.
It seems the advisor is trying to strike partisan balance or build competitive races (as opposed to choosing a plan that sits in the middle of the range of possible maps). His map – and the one we included over the weekend – showed that even if bound by the coherence and non-division of political jurisdictions, one could build a copy. treat both sides almost equally. Notably, he did so while keeping most of the residential centers together. This map passed all three of our tests for partisan asymmetry.
This result is consistent with the unwritten rule of the court’s decision on partisan symmetry: if the two parties swap total votes, their total seats must also be swapped. This equity principle underpins our proposed standards for gerrymandering detection, as described in short amicus in the Whitford case.
It is often said that partisan bias stems naturally from the way voters distribute themselves. Certainly such bias can be seen if one randomly draws thousands (or millions) of maps. But distraction is not an accidental process. It is done by humans and reflects real-world political and social considerations. In that respect, we should not be interested in millions of maps; we should only be interested in a map, a map that is drawn. Persily has shown that it is possible to maintain all the old principles of geographic contiguity, and still create an overall map that does not give undue advantage to either side. In my opinion, this is a big deal because it shows that the ideal of partisan symmetry could be the main criterion for mapping.
Pennsylvania GOP made a disastrous appearance. The Governor and Democrat lawmakers have come up with a plan that could retain some of the GOP’s advantages. The new plan completely eliminated that advantage. In our analysis, based on 2016 votes, the new map manufacturing 5 Democratic districts, 7 Republican districts and 6 subversive districts. The Democrats’ maximum performance for 2018 will be 11 seats, up 6 seats from their current representative. That increase would be a quarter of the 24 seats they need to gain control of the House of Representatives. Of course, some of those interests may also disappear in a year which is good for Republicans as well. That is the point of electoral competition.