(Reuters) - North Carolina's divided Supreme Court struck down the state's new congressional map on Friday, upholding claims from Democratic voters and advocacy groups that the redrawn district lines illegally favor Republicans.
The 4-3 decision, with justices registered as Democrats making up the majority, could have an outsized impact on the 2022 midterm elections in November, when control of the closely divided U.S. Congress will be at stake.
Democrats and civil rights activists had asserted that the new map ensures Republicans will win a majority of the state's 14 congressional districts, even in elections in which more Democratic voters cast ballots.
Issuing a ruling Friday, the Supreme Court said the maps "are unconstitutional beyond a reasonable doubt under the free elections clause, the equal protection clause, the free speech clause, and the freedom of assembly clause of the North Carolina Constitution."
North Carolina's legislature can submit new congressional and state legislative districting plans "that satisfy all provisions of the North Carolina Constitution," the court said. The deadline to submit such plans for review by a trial court is Feb. 18, the court said.
Federal law requires states to draw new congressional lines every 10 years to account for population shifts, after the U.S. Census completes its once-a-decade count. In most states, legislators control the process, leading to the practice of gerrymandering, in which one party engineers political maps to benefit itself.
The case was among numerous pending lawsuits challenging congressional maps in at least half a dozen states, including Texas, Ohio and Georgia, according to New York University's Brennan Center for Justice, which is tracking redistricting litigation.
Republicans need to flip only a handful of seats in the Nov. 8 elections to retake control of the U.S. House of Representatives, where Democrats hold a 221-212 edge, including vacancies.
(Reporting by Rami Ayyub; Editing by Cynthia Osterman)