A federal court ruled Monday that Wisconsin state voting districts drawn by Republicans are unconstitutional.
A three-judge panel threw out the state's district maps, saying they violate the voting rights of Democrats in the state.
The latest maps were drawn up by the Republican majority five years ago.
State Republicans say the districts better represented a shift toward Republican thinking the state over the past several years.
However, a group of 12 Democratic voters filed a lawsuit against the state last year claiming the new maps were designed to dilute their voting power.
"If you went back and looked at the votes in Wisconsin in 2012, and you added up all the Democratic votes and all the Republican votes for the 99 assembly districts, the Democrats had about 150,000 more votes than the Republicans. Under normal democratic system, you would assume they would have taken over the legislature. They did not, it didn't even come close," said UWL Political Science professor Joe Heim.
Heim says the ruling could have a big impact on district maps across the country and create more contested races.
"Right now, legislators pick their own voters rather than voters pick their own legislators. They design the districts to advantage themselves. Competition breeds competition and you want competition in the legislative districts. Safe districts really skewer the way decisions in legislatures operate," said Heim.
In a statement, Wisconsin Attorney General Brad Schimel said the state's district map didn't change the result of the election and he plans to appeal the decision.