COLUMBUS, Ohio (AP) — The Ohio Supreme Court rejected a second Republican-drawn map of U.S. House districts as gerrymandered on Tuesday, sending it back for a third attempt to meet constitutional parameters approved by Ohio voters.

The ruling adds to a string of court defeats for Ohio’s ruling Republicans amid the once-per-decade redistricting process that states undertake to reflect population changes from the U.S. Census. Despite those failures in court, however, Ohio’s 2022 congressional primaries went forward on May 3 under an earlier invalidated U.S. House map, and its legislative primaries under an unconstitutional Statehouse map take place Aug. 2.

New maps will not be put in place until 2024.

In its 4-3 ruling, the court said the latest map — which was passed earlier this year by the Ohio Redistricting Commission without Democratic support — again violated a 2018 constitutional amendment aimed at preventing partisan gerrymandering.

The map created 10 safe Republican seats and five Democratic seats. However, the high court’s majority said the latest map “packed” Democrats into three congressional districts that would heavily favor a Democratic candidate, while unfairly splitting counties and cities around heavily-Democratic Cleveland, Cincinnati and Columbus.

GOP commissioners called it their best attempt at avoiding partisan favor while abiding by the Constitution’s specific provisions, which are in use this decade for the first time.

Majority justices said evidence showed a map that didn’t “unduly favor” Ohio’s majority party would have at least six Democratic-leaning districts, leaving nine Republican-leaning districts. The justices cited studies by several election experts hired by the voting-rights and Democratic groups who challenged the maps.

The decision returns the map to the Republican-controlled General Assembly, which will have 30 days to act.

If lawmakers fail, the debate will return once more to the redistricting panel, whose multiple maps of legislative and congressional districts have yet to withstand court scrutiny.

Ohio’s attorney general, who serves as the Redistricting Commission’s lawyer, does not have the option to appeal, as voters gave the Supreme Court original and exclusive jurisdiction.

In their dissent, Justices Sharon Kennedy and Pat DeWine — son to Gov. Mike DeWine, who sits on the redistricting panel — argued that the constitution doesn’t define what “unduly favors” means and that the majority’s analysis is faulty. They said proportional party representation is not even “an aspirational goal” of the constitution, “much less a requirement.”

The decision “demonstrates that the majority has once again assumed an oversized role in the process of drawing a congressional-district map by perpetuating its own standard of what constitutes ‘unduly favoring’ a political party,” the dissenters wrote.

In a separate dissent, Justice Pat Fischer asserted that the state’s high court should serve as a “trial court” in such disputes, but said that didn’t take place during this first use of Ohio’s new map-making process.

Moderate Republican Chief Justice Maureen O’Connor, who at 70 years old must leave the court Dec. 31 due to age limits, again provided a pivotal swing vote, joining the court’s three Democrats in the majority. O’Connor had also joined Democrats in the ruling against the first congressional map.

Jen Miller, executive director of the League of Women Voters of Ohio, said the group agrees that the districts are “rigged for politicians rather than being drawn to uphold the rights of Ohioans to have meaningful elections.” They hope mapmakers will “take the Ohio Constitution seriously and create maps that truly are fair for the people of Ohio,” she said.