KEYSTONE CROSSROADS -- Testimony in a fast-tracked lawsuit alleging gerrymandering got underway in Pa. Commonwealth Court Monday. The case could force a new state congressional map before the 2018 midterm election.
Eighteen registered Democrats -- one from each congressional district -- claim Pennsylvania's map was drawn unfairly by state GOP leaders to advantage Republicans.
Congressional maps have to follow certain rules, such as distributing equal numbers of voters between districts. Advocates for fairer congressional maps say it's also a best practice to avoid dividing counties and municipalities when drawing district boundary lines.
The plaintiffs' first witness, political scientist Jowei Chen, testified that this clearly wasn't adhered to in Pennsylvania.
Chen, who's published a handful of peer-reviewed studies of redistricting and political geography, used computer models to generate 1,000 random simulations of Pennsylvania's congressional map. On average, these versions divided less than half as many counties as the current one.
Chen also used actual precinct-level vote totals to simulate election outcomes for each of his maps, and each iteration yielded a more balanced Pennsylvania congressional delegation.
For the last three election cycles, voters have elected 13 Republicans and five Democrats to represent the state in Washington, D.C. Democrats hold a significant advantage in voter registration in the state.
Chen said he did not have direct knowledge of exactly how Pennsylvania's map was drawn. But, based on map-building computer files, he testified that he believes that precincts' partisan leanings might have been used.
He said the files' data columns had headings such as "prez08," referencing specific elections, with numbers correlated to how heavily each precinct leaned Republican or Democrat during the corresponding contest.
Chen also determined that some of the plaintiff Democrats, who currently reside in Republican-leaning districts, would be living in Democratic-leaning districts in the vast majority of his simulations.
The map in question was passed in 2011 when Republicans controlled all three branches of government. It was enacted, though, with significant support from Democrats, many of whose incumbents in Congress were seemingly given safer districts.
Several national studies have determined Pennsylvania to be one of the most gerrymandered states in the country. In Maryland, where the process was controlled by Democrats, experts also cite extreme gerrymandering. Last week, the U.S. Supreme Court agreed to hear a case challenging that map.
In a federal trial concerning Pennsylvania's congressional map held last week in Philadelphia, Republican legislative aides testified that partisan data was used to draw district boundary lines -- this in addition to candidate incumbency and compliance with the Voting Rights Act, among other factors.
The U.S. Supreme Court has previously ruled that politics can play a role in determining district boundaries. Attorneys for Republican leaders in the legislature, named as defendants in the case, argue that the political balance of the state's congressional delegation would be more equal if Democrats ran better candidates.
The defense is expected to cross-examine Chen on Tuesday, and bring in their own expert to counter his testimony.
Two plaintiffs also testified Monday, saying that the state's congressional map has made their representatives less responsive, and has driven apathy and frustration among voters.
This week's court proceedings are before Commonwealth Court Judge Kevin Brobson, but will be used by the Pa. Supreme Court to rule on the matter. A decision is expected early next year.