The Pennsylvania Legislative Reapportionment Commission released new district maps for the Pennsylvania House and Senate today.
As we predicted, the maps look very different from the current ones because they aim to adjust for dramatic population changes over the last ten years and to remedy two decades of Republican gerrymandering.
Because they do so, both maps are fairer and more representative of the people of Pennsylvania than the old ones.
At this moment, we do not have detailed information about the Senate redistricting plan so we cannot comment on it in depth.
We do have data on the House redistricting plan, however. The three standard metrics of redistricting we used in our earlier piece show that the plan has a slight Republican tilt compared to the heavy Republican tilt of the maps in 2012 and 2002. Between the current map and the new one, the Republican advantage according to the efficiency gap metric is reduced from 7.0% to 2.3%. The Republican advantage according to the partisan bias metric is reduced from 7.5% to 2.5%. The Republican advantage according to the mean-median metric is reduced from 6.2% to 1.0%.
The remaining Republican tilt in the plan is, no doubt, a product of the tendency of Democratic voters to clump together in urban areas, along with the difficulty of truly undoing entrenched gerrymandering, acknowledged by commission chairman Mark Nordenberg. As we pointed out in our original report, this makes drawing a map without a Republican partisan advantage difficult in many places, including Pennsylvania.
But the Legislative Reapportionment Commission has done an excellent job, given these limitations.
Republicans are already complaining about these districts because they are very different from the current ones; not only is their advantage much reduced but a number of Republican incumbents have been placed in the same districts (as have a number of Democrats).
This is what we predicted in our report. The dramatic demographic change in the state’s population, combined with an effort to undo two decades of extreme gerrymandering, is bound to create districts that are dramatically different. From the perspective of good government, this is an impressive accomplishment.