WASHINGTON — The Supreme Court on Monday struck down two North Carolina congressional districts, ruling that lawmakers had violated the Constitution by relying too heavily on race in drawing them.
The court rejected arguments from state lawmakers that their purpose in drawing the maps was not race discrimination but partisan advantage.
Election law experts said the ruling would make it easier to challenge voting districts based partly on partisan affiliations and partly on race.
“This will lead to many more successful racial gerrymandering cases in the American South and elsewhere,” said Richard L. Hasen, a law professor at the University of California, Irvine.
Democrats welcomed the ruling.
“This is a watershed moment in the fight to end racial gerrymandering,” Eric H. Holder Jr., the former attorney general and the chairman of the National Democratic Redistricting Committee, said in a statement. “North Carolina’s maps were among the worst racial gerrymanders in the nation.”
The justices were unanimous in rejecting District 1, in the northeastern part of the state. After the 2010 census, lawmakers increased the district’s black voting-age population to 52.7 percent from 48.6 percent.