Pennsylvania's Democratic Gov. Tom Wolf on Tuesday rejected a revised congressional map submitted by the state's Republican legislature after independent analyses found that the new map was just as biased in favor of the GOP as the old map.
“Like the 2011 map, the map submitted to my office by Republican leaders is still a gerrymander,” Wolf said in a statement. “Their map clearly seeks to benefit one political party.”
In addition to the outside analyses, the governor's office presented the conclusions of Tufts University mathematician Moon Duchin. Duchin used an algorithm to generate “millions of alternative districting plans” according to the state's traditional redistricting criteria.
The new map's “bias in favor of Republicans is extremely unlikely to have come about by chance,” Duchin wrote, putting the odds of such a map at roughly 0.1 percent. The new map “is indeed an extreme outlier, exhibiting a decidedly partisan skew that cannot be explained by Pennsylvania’s political geography or the application of traditional districting principles.”
Last month, Pennsylvania's Supreme Court ruled that congressional districts drawn by the Republican legislature following the 2010 Census were an illegal partisan gerrymander that deprived the state's voters of their right to participate in “free and equal” elections. In each election held since that map was drawn, Democratic candidates won close to 50 percent of the statewide House popular vote but picked up just five of the state's 18 U.S. House seats.
Republican lawmakers accomplished this feat in 2011 by drawing sprawling, oddly shaped district boundaries to pack Democratic voters into the smallest number of districts possible. The districts became the butt of national jokes, earning nicknames such as “Goofy kicking Donald Duck.”
After the court's ruling, Republican leaders late last week submitted a new map with much more compact borders that they said complied with the court's order. “The proposed map fully complies with all the metrics laid out by the plaintiff experts in the case as well as the tests set forth in the majority opinion by the Supreme Court of Pa.," said Drew Crompton, general counsel to Pennsylvania's state Senate Republicans, in an email.
However, an analysis by redistricting expert Brian Amos of the University of Florida found that the new districts showed nearly the exact same partisan composition as the old ones. That makes it unlikely the new map would change the partisan disparity at the heart of the Supreme Court's ruling.
Redistricting experts point out that it's perfectly possible to draw politically biased districts without resorting to odd, sprawling shapes. Gerrymandering is a function both of who draws the maps and their goals in drawing them. When politicians draw political districts, as is the case in most states, there's a strong incentive for them to draw boundaries that disadvantage their opponents.
Unless Pennsylvania's governor and lawmakers are able to work out their differences by Thursday, the state Supreme Court will take control of the redistricting process with the help of Nathaniel Persily, a redistricting expert at Stanford University who has worked on redistricting cases in a number of other states.
The court will have to move quickly. Any new map will need to be in place before Pennsylvania voters head to the primaries in May.