The Supreme Court on Friday threw out electoral maps drawn by federal judges in Texas that favored minorities. The decision ultimately could affect control of the U.S. House of Representatives and leaves the fate of Texas' April primaries unclear.

The justices ordered the three-judge court in San Antonio to come up with new plans that pay more attention to maps created by Texas' Republican-dominated state Legislature. All four of the state's new congressional seats could swing based on the outcome.

But the Supreme Court did not compel the use of the state's maps in this year's elections, as Texas wanted. Only Justice Clarence Thomas said he would have gone that far.

The court's unsigned opinion thus did not blaze any new trails in election law or signal retreat from a key provision of the Voting Rights Act, as some supporters of the law feared would result from this case.

Still, the outcome appeared to favor Republicans by instructing the judges to stick more closely to what the Legislature did, said election law expert Richard Hasen, a professor at the University of California, Irvine, law school.