CINCINNATI — A federal trial started Monday in an ACLU Ohio lawsuit challenging Ohio’s gerrymandering.

According to the ACLU, due to an aggressive redistricting operation, Ohio’s current congressional map — enacted in December 2011 — is gerrymandered to lock in a 12-to-4 advantage for Republican candidates. Although the number of Democrat and Republican voters in Ohio is roughly even, gerrymandering has allowed the Republican Party to secure 75 percent of the seats in the U.S. House of Representatives in every election since the map was drawn.

The ACLU of Ohio, the ACLU, and the law firm of Covington and Burling challenged that map, seeking to replace it with a new one before the 2020 election. A judicial panel has ruled that the ACLU provided sufficient evidence in discovery to proceed to trial on the claim that Ohio’s map violates the federal Constitution.

“The map has consistently performed exactly as its architects planned, guaranteeing 75 percent of the seats to the Republican Party,” said Freda Levenson, legal director for the ACLU of Ohio. “Not one single seat has changed in all eight elections. It’s critical that the courts remedy this, because obviously Ohio’s voters cannot vote themselves out of this situation.”

Plaintiffs are the Ohio A. Philip Randolph Institute, League of Women Voters of Ohio, Northeast Ohio Young Black Democrats, OSU College Democrats, Hamilton County Young Democrats, and individuals from every congressional district in Ohio.

Named defendants include Ohio Secretary of State Frank LaRose, Ohio House Speaker Larry Householder, and Senate President Larry Obhof.

A three-judge panel — Judges Karen Nelson Moore, Timothy S. Black, and Michael H. Watson — is presiding over the trial.