The ruling, by a three-judge panel from the U.S. District Court in Cincinnati, ordered new maps to be drawn by June 14 to be used for the 2020 election, when Democrats will fight to preserve their House majority. The ruling will go directly to the U.S. Supreme Court for review.
The ruling follows decisions by four other federal courts striking down partisan gerrymanders in Wisconsin, North Carolina, Maryland and, last week, in Michigan. All but Maryland were gerrymandered by Republicans.
The Supreme Court is expected to rule this spring in appeals from Maryland and North Carolina.
The rulings in those cases could determine whether the Supreme Court upholds this decision, alters it or nullifies it.
Ohio’s maps, in effect since 2012, have solidified a congressional delegation that has remained unchanged in four elections, yielding 12 Republicans and four Democrats — or 75 percent for one party in a swing state that has trended Republican in recent years, but where presidential and statewide elections are often close.
In their sharply worded, unanimous opinion, the judges wrote that Republicans in Ohio, supervised by party mapmaking experts in Washington, operated with “invidious partisan intent” to pack Democrats into as few districts as possible, and to carve up Democratic-leaning cities and counties to favor Republicans.
Hamilton County and Cincinnati, for example, were split in a “strange, squiggly, curving shape” to divide Democrats, the judges wrote. Meanwhile in Franklin County, which includes Columbus, Democrats were concentrated in a “sinkhole” that allowed mapmakers to “secure healthy Republican majorities” in two suburban districts.
Republicans’ representatives argued at trial that the maps were drawn to protect incumbents of both parties and that there was nothing illegal in doing so.
The three judges, two of whom were appointed by Democratic presidents and one by a Republican president, disagreed.
“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 judges wrote in their 301-page decision.