In 2016, North Carolina Republicans got caught.

It was seven months before the presidential election, and a panel of three federal judges ruled GOP lawmakers had illegally diluted the black vote by packing African American voters in two congressional districts. They told the lawmakers, who had a super-majority in the state legislature, to come up with a new map in just two weeks.

State Rep. David Lewis (R), one of the chairs of the redistricting committee, openly acknowledged at the time that Republicans were trying to use political data to maximize their partisan advantage. I propose we draw a map to give a partisan advantage to 10 Republicans and three Democrats because I do not believe its possible to draw a map with 11 Republicans and two Democrats, Lewis said during a legislative meeting . Republicans implemented a new map that did just that. (Lawyers representing Lewis now say the comment was meant to be a joke.)

The committee hired an expert mapmaker and told him to comply with federal requirements for drawing congressional districts. But it set out two other crucial criteria: He could not consider race and he had to draw a plan that allowed Republicans to maintain 10 of the states 13 congressional seats the same advantage they had under the map that was unlawfully racially gerrymandered.

The Supreme Court on Tuesday will hear oral arguments in a closely watched case seeking to strike down that map that was drawn in 2016.

The plaintiffs in the case say Lewis comments offer evidence of unconstitutional intent to hurt Democratic voters. The circumstances in North Carolina, they say, offer a clear and unique opportunity for the court to place limits on partisan gerrymandering, something it has repeatedly declined to do.

The Supreme Court consolidated the North Carolina case with a separate but similar lawsuit from Maryland. In the Maryland case , Republican voters in one congressional district say Democrats violated their First Amendment rights when they redrew the district in 2011 to flip it from a Republican one to a Democratic one.