A federal court on Tuesday ruled that Republicans in North Carolina unconstitutionally gerrymandered congressional districts in 2016 to ensure Republican “domination of the state’s congressional delegation.”

The three-judge panel struck down the map and ordered the state’s General Assembly to come up with a substitute by Jan. 24.

The decision was the first striking down a congressional map, as opposed to state legislative maps, on the grounds that it was rigged in favor of a particular political party. Redistricting has historically always been political and partisan to one degree or another.

While courts have invalidated redistricting plans, including ones in North Carolina, as racially discriminatory, judicial objection to gerrymandering for partisan gain is relatively new territory with legal standards unsettled by the U.S. Supreme Court.

Two cases currently under consideration by the high court, one from Wisconsin and another from Maryland, may provide guidance in the area.

If North Carolina appeals Tuesday’s decision, the Supreme Court could very well add that case to its docket.

Tuesday’s decision was made easier for the panel by a smoking gun: Republican leaders in the North Carolina General Assembly openly conceded that the 2016 map was drawn to benefit Republicans.

They hired a consultant from the Republican National Committee to draw the map and excluded Democrats from participation in the process, the court panel found.

That consultant, the court said, testified that he was told “to minimize the number of districts in which Democrats would have an opportunity to elect a Democratic candidate.”

“Rather than seeking to advance any democratic or constitutional interest,” the panel wrote in a lengthy opinion, “the state legislator responsible for drawing the 2016 plan,” Rep. David Lewis, openly declared that he drew the drew the map to advantage Republican candidates because he thinks “electing Republicans is better than electing Democrats.”

But that, said the panel, “is not a choice the Constitution allows legislative mapdrawers to make.”

The Republican-dominated House and Senate in North Carolina set out to entrench Republicans and succeeded in doing so, the panel declared.

The plan was designed to give Republicans victories in 10 of the state’s 13 districts, and did just that.