Jonathan Cervas and Bernie Grofman have posted this draft on SSRN. Here is the abstract:

In League of Women Voters v. Commonwealth of Pennsylvania (2018) the Pennsylvania Supreme Court struck down a congressional plan that embodied one of the most egregious partisan gerrymanders of the 2010 redistricting round. It did so entirely on state law grounds after a three-judge federal court had rejected issuing a preliminary injunction against the plan. Here we examine the ruling and the expert evidence it relied on. We also contrast the criteria used to evaluate partisan gerrymandering by this court with those used by the federal three judge panels that found unconstitutional levels of partisan gerrymandering in plans in Wisconsin and North Carolina, and we compare it to the so far unsuccessful challenge in Maryland. In our concluding discussion we review the key lessons to be learned from this case, and the implications of the case for other jurisdictions, especially those in the twelve states whose state constitutions have provisions similar or identical to the one relied upon by the Pennsylvania Supreme Court.