On February 15, 18 voters and the League of Women Voters of Pennsylvania submitted two proposed remedial congressional districting plans to the Pennsylvania Supreme Court. The petitioners are represented by Arnold & Porter and the Public Interest Law Center.
In compliance with the Pennsylvania Supreme Court’s January 22 order, the petitioners and their legal team worked with expert witness Dr. Jowei Chen to generate two non-partisan congressional district maps that comply with the Court’s order and Pennsylvania’s constitution.
“Dr. Chen’s algorithm created districting plans based exclusively on the traditional districting principles that the Pennsylvania Supreme Court identified: equal population, contiguity, avoiding splitting political subdivisions, and compactness,” said Dan Jacobson of Arnold & Porter. “No partisan data went into the creation of these maps.”
“Unlike the 2011 congressional map, these maps have not been surgically reconstructed to obstruct voter participation,” said Mimi McKenzie of the Public Interest Law Center. “Instead of a manipulated, gerrymandered map that benefits one political party over another, these maps are fair and put the steering wheel of democracy back in the hands of Pennsylvania voters.”
The first map, Map A, was one of the maps Dr. Chen presented during trial. The second map, Map B, was generated by Dr. Chen using a slight adjustment to his algorithm to weight county and municipality splits equally, and to expressly avoid splitting precincts and wards.
After the algorithm generated the maps, the petitioners worked with their expert on Pennsylvania political geography, Dr. John Kennedy. Dr. Kennedy identified which of Dr. Chen’s maps stood out as best preserving communities of interest.
Dr. Chen’s algorithm did not incorporate racial data or considerations. However, both of the petitioners’ proposed maps maintain a majority-minority district in the 2nd District. Map A contain a second majority-minority district in District 13. Map B contains two additional districts (1 and 13) in which minority voters in aggregate comprise roughly 40% of the voting age population.
Analyzed using the same prediction methodology Dr. Chen presented at trial, both maps produce a 9-9 split between expected Republican and Democratic seats, a marked difference from the 2011 map’s durable, lopsided, 13-5 majority in favor of Republicans. A 9-9 split is the most common outcome across all of Dr. Chen’s randomly generated maps using only traditional redistricting criteria.
The petitioners’ brief can be viewed here.
The petitioners’ shapefiles can downloaded here.
Other shapefiles and case documents can be accessed here.