The panel blocked Ohio lawmakers from using the map in any future elections, and it gave lawmakers until June 14 to come up with a new plan.
Republicans controlled the redistricting process in 2011 and drew lines that gave them a 12-4 electoral advantage in the state’s congressional delegation. They have maintained that advantage since.
The court said the map violated the First and 14th amendments of the U.S. Constitution, as well as Article I. Article I gives states the power to draw electoral lines, but it also says members of the U.S. House shall be chosen by the people.
By gerrymandering, Ohio lawmakers blocked people from choosing their preferred members of the House.
“We are convinced by the evidence that this partisan gerrymander was intentional and effective and that no legitimate justification accounts for its extremity,” the panel wrote. “Performing our analysis district by district, we conclude that the 2012 map dilutes the votes of Democratic voters by packing and cracking them into districts that are so skewed toward one party that the electoral outcome is predetermined.”
The court noted it was joining several other federal courts that have recently struck down partisan gerrymanders as unconstitutional. Federal panels in Michigan, Wisconsin, North Carolina and Maryland have all blocked electoral districts on grounds that they too severely favored one party over another.
The suit was filed last year by the American Civil Liberties Union on behalf of two civic groups and voters in each of the state’s 16 congressional districts.
Despite that growing consensus, the Supreme Court appears wary of allowing federal courts to evaluate electoral maps and block them when they are too severely gerrymandered on partisan grounds. The North Carolina and Maryland cases are currently pending before the Supreme Court; during oral argument in March, the justices seemed divided on whether there was a way to determine when redistricting ― a task delegated to a political branch of government ― crossed from politics as unusual to unconstitutional gerrymandering. The Supreme Court is set to rule on the North Carolina and Maryland maps by June, and the outcome in that case will determine the ultimate outcome of what happens in Ohio, Michigan and Wisconsin.