GREENSBORO, N.C. (AP) — A federal trial scrutinizing nearly 30 North Carolina legislative districts concluded Friday after attorneys presented conflicting arguments over whether increasing the number of majority-black districts reinforces outdated race-based political divisions or is a sensible legal strategy.

The three-judge panel gave no timeframe on when it would rule at the close of the weeklong trial spurred by a voters’ lawsuit, but any decision is at least several weeks away and could be appealed.

The timing of the ruling could determine whether Republican lawmakers have to scramble to redraw boundaries in time for the November general elections. The state’s lawyers, who are defending the current boundaries as legal, have said that if any adjustments are ordered, they should be delayed until the 2018 elections.

Some of North Carolina’s congressional boundaries were struck down as illegal racial gerrymanders by a different federal judicial panel in February, based in part on arguments similar to what the plaintiffs used in this week’s case. The legislature, forced to redraw the congressional districts right away, delayed the primary for the seats until June 7. Legislative primaries under the current maps were held last month.

Current and former Democratic legislators, some of the voters who sued, and redistricting experts testified during the week as the plaintiffs offered evidence showing there was no need for GOP legislative leaders to draw so many House and Senate districts with black voting-age populations above 50 percent.

There were 32 such districts in the 2011 maps, compared to just 10 in the maps drawn by mostly Democratic legislators in the 2000s, when black candidates were winning seats in districts where black voting-age populations were closer to 40 and 45 percent, according to the lawsuit. That’s because the preferred candidates of black voters were winning with a coalition of white voters, said Anita Earls, one of the voters’ attorneys. She said some majority-black districts were legally necessary.

Those election results were in the hands of Republican legislators at the time of the 2011 redistricting debate, Earls said during her closing argument, but they voted to raise the black population in these districts above 50 percent anyway, which she said violated the U.S. Voting Rights Act.

“The districts were drawn without taking this information into account,” Earls said, resulting in districts that needlessly packed black voters in districts, creating a form of segregation. “These maps send a message about race and how we use race.”

Critics of the GOP-drawn plans have said the challenged maps dilute the influence of black voters in adjoining districts, making them more white and Republican. The current House and Senate boundaries have been used in the 2012 and 2014 elections, helping Republicans expand their majorities.

Tom Farr, a private attorney representing the state, said the plaintiffs’ experts ignored many legislative races where the black candidate lost in districts with black voting-age populations that were sizable but less than 40 percent. That shows racial polarization in voting still exists, he said.

Farr told the judges a 2009 U.S. Supreme Court decision says legislators can find safe harbor from Voting Rights Act liability when they draw majority-black districts in areas that can support them.

“There was a fear of being sued under lots of grounds, your honor,” he told U.S. District Judge Thomas Schroeder. Also hearing the case were District Judge Catherine Eagles and U.S. Circuit Judge Jim Wynn.

The voters who sued also failed to provide alternate maps that would comply with both federal redistricting rules and state criteria and give guidance to the judges, Farr said. “All they’ve done is thrown darts at the enacted plans,” he said.

Sen. Bob Rucho, R-Mecklenburg, and Rep. David Lewis, R-Harnett, who led the General Assembly’s redistricting effort five years ago, testified during the week. On Friday, Thomas Hofeller, an outside mapmaker who helped draw the actual maps for Republicans, talked on the stand about how he arrived at creating the majority-black districts. He said a state redistricting requirement designed to minimize the district lines that cut through county boundaries makes North Carolina’s maps more complicated “than just about any state in the nation.”