The Supreme Court on Monday sent back to a lower court a decision that Republicans in North Carolina had gerrymandered the state's congressional districts to give their party an unfair advantage.
The lower court will need to decide whether the plaintiffs had the proper legal standing to bring the case.
The Supreme Court recently considered the question of partisan gerrymandering in cases from Wisconsin and Maryland. The court has never found a map so infected by politics that it violated the constitutional rights of voters.
But the justices did not rule on the merits of the issue. The court said plaintiffs in Wisconsin did not have the proper legal standing and that the Maryland case was in too preliminary a stage.
North Carolina's Republican-led legislature has implemented a map under which Republicans hold 10 of the 13 congressional seats. The GOP's domination of the congressional delegation belies North Carolina's recent history as a battleground state. It has a Democratic governor and attorney general, who have declined to defend the maps.
When a three-judge panel invalidated the map of congressional districts, it became the first to strike a congressional map on the grounds that it was rigged in favor of a political party.
North Carolina has a past at the Supreme Court, with redistricting plans struck down as racial gerrymanders. So when the state legislature adopted new plans in 2016, Republican leaders made clear they were drawing the lines to help their party, instead of basing their decisions on racial data.
"I think electing Republicans is better than electing Democrats," said Rep. David Lewis, a Republican member of the North Carolina General Assembly. "So I drew this map to help foster what I think is better for the country."
He added: "I propose that we draw the maps to give a partisan advantage to 10 Republicans and 3 Democrats because I do not believe it's possible to draw a map with 11 Republicans and 2 Democrats."
When voters went to the polls that fall, the outcome was exactly as Lewis had predicted, even though Republican candidates won just 53 percent of the statewide vote.
The case is Rucho v. Common Cause.