After the 2010 census, the Wisconsin Legislature’s Republican leadership asked an outside attorney to advise it on redrawing district maps. The lawyer, hired at taxpayers’ expense, did his work in a private map room, which Republicans could enter only if they signed a confidentiality agreement. That offer didn’t extend to Democrats, who first saw the proposed changes when they were formally introduced. The new maps were adopted by the Republican-controlled state senate and assembly days after being made public.
In July attorneys sued on behalf of 12 Wisconsin voters who claim that the redistricting, which was in effect for the 2012 presidential election and the 2014 midterm, was unfairly partisan. The case is rooted in a 2014 paper co-written by Nicholas Stephanopoulos, an assistant professor at the University of Chicago Law School, that examined almost every redistricting since 1972. Stephanopoulos, who’s one of the lawyers on the Wisconsin case, tried to quantify the results. Gerrymandering generally follows one of two patterns: packing, the cramming of one party’s voters into a single district; and cracking, spreading a party’s voters across many districts to deny them the chance of reaching a majority.
In a packed district, votes above 50 percent for the majority party are wasted, whereas in a cracked one all votes for the minority party are lost, according to Stephanopoulos’s theory. “Even a very fair plan results in lots of wasted votes,” he says—but unfair plans result in one party wasting far more votes than the other, which he calls an efficiency gap. The Wisconsin gerrymander, according to the plaintiffs, was more effective at giving one party an electoral advantage than 96 percent of the political maps he examined.
The Supreme Court ruled in 1986 that gerrymandering could, in theory, be unfairly partisan, but it’s never established a way to determine when redistricting crosses the line. Stephanopoulos says he hopes the Wisconsin case will establish the efficiency gap as the standard for gauging the fairness of election maps.
The state has asked the court to dismiss the case, saying the efficiency gap “is based on the same principle the Supreme Court has repeatedly rejected”—the idea of partisan symmetry, that votes should translate to seats at the same proportion for each party. The problem, the state says, isn’t a matter of crafting a new formula. Instead, it’s that “no one can articulate a constitutional principle defining what should be measured.”
In October a federal district court assigned a three-judge panel to review the case. The trial is set for May 2016. Stephanopoulos says the court should rule quickly. If he prevails, he says, “we want a new map—a fair map—in place for 2016.”