RALEIGH, N.C. — Federal judges on Monday affirmed their earlier decision striking North Carolina's congressional districts as unconstitutional because Republicans drew them with excessive partisanship.

Acting under an order of the U.S. Supreme Court to re-examine the case, the three-judge panel ruled again in favor of election advocacy groups and Democrats who had sued to challenge the boundaries drawn in 2016.

The Greensboro-based court also raised the possibility of directing the GOP-dominated legislature to redraw the maps by mid-September so they could be in effect for the fall elections, or getting an outside expert to do so. The printing of ballots has been delayed while other fall election matters are in court.

"In such circumstances, we decline to rule out the possibility that the state should be enjoined from conducting any further congressional elections using the 2016 plan," U.S. Circuit Judge Jim Wynn wrote in the majority opinion. He asked lawyers in the case to weigh in by Friday about what should happen next.

Any decision demanding new maps for this cycle likely would risk confusion among voters and be appealed by the Republican legislative leaders being sued.

May primaries were held, and general election candidates are raising money and campaigning in the current districts while approaching a mid-term election in which control of the House is at stake. Even the plaintiffs, in their news releases praising the ruling, said they anticipated the Supreme Court would hear appeals during its session starting in October, meaning any new maps probably wouldn't be used until the 2020 cycle.

The groups and individuals that sued alleged GOP mapmakers manipulated the lines of the state's 13 districts in 2016 using political data to ensure Republicans retained a 10-3 majority within the delegation.

The same judges in January deemed the map an illegal partisan gerrymander that violated constitutional protections of Democratic voters. But the Supreme Court, which had ruled against plaintiffs in a redistricting case in Wisconsin, asked them to take a second look in June.

The sides in the case then filed briefs and provided new evidence. In Monday's order covering almost 300 pages, Wynn wrote that at least one plaintiff registered to vote in each of the 13 districts has legal standing to challenge their district — meeting a key element of the justices' ruling in the Wisconsin case. In each case, the opinion reads, the voter offered evidence showing the district had been twisted so that the person's vote carried less weight compared to another hypothetical district that hadn't been packed or split for partisan results.

The U.S. Constitution "does not allow elected officials to enact laws that distort the marketplace of political ideas so as to intentionally favor certain political beliefs, parties, or candidates and disfavor others," Wynn wrote.

Wynn, District Judge Earl Britt and District Judge William Osteen agreed again that the 2016 redistricting plan violated the U.S. Constitution's equal-protection provision. They also ruled that it violated provisions requiring states to be in charge of congressional elections because it dictated electoral outcomes. Osteen, in a separate opinion, disagreed with decisions by Wynn and Britt that the map also violated the First Amendment rights of Democrats to freedom of speech and of association.

Spokespeople for Republican legislative leaders didn't immediately respond to emails Monday evening seeking comment on the panel's ruling. Their attorneys had argued the three-judge panel should dismiss the lawsuits because the plaintiffs' evidence was statewide in nature, not district by district.

Bob Phillips, executive director of Common Cause North Carolina, called the ruling a historic win for voters, and a significant step towards finally ending gerrymandering."

The map was redrawn in 2016 because other federal courts determined two districts originally drawn in 2011 were illegal because of excessive racial bias.

Wynn noted the decadelong challenges.

"We continue to lament that North Carolina voters now have been deprived of a constitutional congressional districting plan — and, therefore, constitutional representation in Congress — for six years and three election cycles," he wrote.