If liberals can win in April and again in 2020, they would have the majority until at least 2025.

Advertisement Federal court: Wisconsin's Republican-drawn redistricting maps are unconstitutional Share Shares Copy Link Copy

Federal judges struck down Wisconsin's Republican-drawn legislative districts as unconstitutional on Monday, marking a victory for minority Democrats that could force the Legislature to redraw the maps. The ruling by a three-judge panel can be appealed to the U.S. Supreme Court. But it still provides hope for legislative Democrats who have been in the minority for six years and lost more ground in this month's election. The judges didn't order any immediate changes to district boundaries, instead saying they would accept ideas on what to do next within the next 30 days. Republicans, who took full control of state government in the 2010 election, drew the maps in 2011 as part of redistricting required every 10 years. A dozen voters sued, arguing the maps unconstitutionally discriminated against Democrats by diluting their voting power. They called it the worst example of gerrymandering in modern history. Attorneys for the state said the redrawn districts simply reflected that Wisconsin was trending Republican, and argued there is no legal way to measure gerrymandering - the process of dividing districts to gain an unfair advantage. The ruling came from a panel of three judges - U.S. District Judge Barbara Crabb, 7th U.S. Circuit Court of Appeals Judge Kenneth Ripple and U.S. District Judge William Griesbach. Griesbach was appointed by Republican President George W. Bush, Ripple by Republican President Ronald Reagan and Crabb by Democratic President Jimmy Carter. During a four-day trial in May, the voters' attorneys argued that the boundaries represented the worst example of gerrymandering in modern history. They said the maps aimed to marginalize Democrats by packing them into districts that already favored them - thus leading to a lot of wasted votes that could have helped Democrats elsewhere. One effect of the redistricting, according to plaintiff attorney Gerald Hebert, was to reduce the number of swing districts from 19 to 10. The voters also noted that under the new maps in 2012, Republicans won 60 of 99 Assembly seats even though Democrats won a majority of the statewide vote. State attorneys argued that partisanship should be expected when one party draws legislative boundaries. The U.S. Supreme Court has yet to come up with a legal standard for deciding when redistricting becomes unconstitutional gerrymandering. Plaintiff attorneys hoped to establish a new method for measuring partisanship that could be used to challenge voting maps around the country. They offered the judges an equation that included measuring and comparing each party's wasted votes in an election. State lawyers argued the equation lacked any constitutional basis and there was no way a court could measure gerrymandering. Legislators are required to redraw Senate and Assembly district boundaries to reflect population shifts. The job was one of the first tasks Republican lawmakers took on in 2011 after they seized control of the state Senate, the Assembly and the governor's office in 2010.