GREENSBORO, N.C. (AP) — Attorneys for election advocacy groups and Democrats urged federal judges Thursday to throw out North Carolina's congressional districts for excessive partisanship, but lawyers for the Republicans who drew them say it's best the judiciary avoid trying to evaluate an inherently political process.

The arguments from both sides wrapped up a trial this week involving two lawsuits that asked the court to declare a redrawn map for the state's 13 seats an unconstitutional partisan gerrymander. The lawsuits argue that when redoing the map last year, GOP state legislators went too far when they followed criteria designed to retain the party's 10-3 majority.

The districts are so lopsided in terms of Democratic or Republican dominance, they violate the free-speech and equal-protection rights of people aligned with the minority party in each district and give the minority party candidates little chance to win, the plaintiffs argued. The candidate with the smallest margin of victory in the November 2016 elections under the new maps still won with 56 percent of the district's vote.

The beneficiaries of the favored maps — congressional incumbents — have no incentive to make their seats more competitive, said Emmet Bondurant, who represented some of the plaintiffs, including the state Democratic Party and the watchdog group Common Cause. And, he said, the legislature won't stop using political data and partisan considerations.

"If the problem is to be solved, it can only be solved by the judicial branch of government," Bondurant said during closing arguments before the three-judge panel, adding that the North Carolina map was "the textbook example of viewpoint discrimination."

The judges didn't rule immediately, and requested post-trial briefs early next month. The ultimate ruling could be influenced by a Wisconsin case about which the U.S. Supreme Court held oral arguments in October. Justices previously have suggested partisan gerrymandering could be subject to legal sanctions, but have not made a firm ruling on it.

Attorneys for the League of Women Voters of North Carolina and several individual voters who also sued called math and political science experts as witnesses to testify that the only explanation for the makeup of the 2016 congressional map was partisanship.

"The people of the state deserve better," said League attorney Anita Earls.

Phil Strach, an attorney for the Republican mapmakers, said the plaintiffs were blowing the partisanship factor out of proportion. They said legislators considered several factors when rewriting the map aside from protecting incumbents, such as creating districts with compact shapes.

Strach said alternate formulas offered by some of the plaintiffs fall short and judges should be skeptical about using them.

"The Holy Grail has not been found in the case," Strach said. He said the court shouldn't base its decision on predictions that the delegation will remain 10-3 in favor of Republicans. Voters have shown they don't follow predicted trends, he said, pointing to the 2010 elections when Republicans took majorities in both chambers of the General Assembly based on maps drawn largely by Democrats.

The plaintiffs "are asking this court to pull out their crystal ball," he said. "We would suggest that a crystal ball is not a constitutional standard."

U.S. District Judge William Osteen — hearing the case with Circuit Judge Jim Wynn and District Judge Earl Britt — offered most of the questions during closing arguments. He asked Bondurant whether perhaps the public was equipped to address gerrymandering by voting out of office the party that drew the partisan maps.

"There's no evidence there's been any attempt to remedy this through the political process," Osteen said.

Democrats and their allies would argue that has been difficult to do because of General Assembly districts drawn in 2011, which helped the GOP extend and retain veto-proof majorities. Federal judges last year threw out nearly 30 districts as illegal racial gerrymanders. The legislature redrew House and Senate maps in August. They are now being scrutinized by another three-judge panel that includes Wynn.