Wisconsin's Central Role in the Future of Partisan Gerrymandering

On October 3, the Supreme Court heard oral arguments in the case Gill v. Whitford.

The basic facts are that Republicans, having gained control of both houses of the Wisconsin legislature and the Governorship in 2010, enacted a legislative-redistricting plan, known as Act 43, designed to maximize their chances of maintaining a legislative majority under any likely future voting scenario. Over the course of several months, lawyers and political scientists used sophisticated statistical techniques and map-drawing software to prepare various maps.

They evaluated the degree to which each proposed map would improve Republicans’ electoral prospects. The maps ultimately chosen resulted in a substantial Republican advantage: in 2012, the state-wide Republican vote share was 48.6 percent, yet Republicans won 61 percent of all Assembly seats; in 2014, the Republicans won 64 percent of the seats with a vote share of 52 percent.