The Supreme Court on Friday rejected elections maps drawn by a federal court in Texas that had favored Democratic candidates there.
The unanimous decision said that redistricting is primarily a job for elected state officials and that the lower court had not paid enough deference to maps drawn by the State Legislature, which is controlled by Republicans. The justices sent the case back to the lower court, extending the uncertainty surrounding this major voting-rights case.
The new maps to be drawn by the lower court could play a role in determining control of the House of Representatives. Democrats need a net gain of 25 seats to take back the House from Republican control, and both parties are fighting for every advantage in the battle for the House majority. Experts in election administration said the new maps could influence outcomes in perhaps three Texas districts.
“A district court should take guidance from the state’s recently enacted plan in drafting an interim plan,” the Supreme Court’s unsigned decision said. “That plan reflects the state’s policy judgments on where to place new districts and how to shift existing ones in response to massive population growth.”
The changes to the electoral maps were required because Texas grew by more than four million people in the last decade, with about 65 percent of that growth coming in the Hispanic population. The growth entitled the state to four additional House seats. In rejecting significant aspects of the Legislature’s maps, the lower court said it had tried to ensure that Hispanic voters had adequate opportunities to elect candidates of their choice, adding that political considerations had played no role.
“This is a big win for Texas, and will require the drawing of districts much more likely to favor Texas’s interim plan,” Richard L. Hasen, an election law expert at the University of California, Irvine, said in an e-mail. The new maps, Professor Hasen said, would “favor Republicans over Democrats” as compared with the lower court’s original maps.
Greg Abbott, the attorney general of Texas, expressed satisfaction with the decision.
“The Supreme Court confirmed that the San Antonio court drew illegal maps, without regard for the policy decisions of elected leaders,” Mr. Abbott said in a statement.