This blog originally appeared at THE NEW YORK TIMES.

In a departure from decades of precedent, the U.S. Court of Appeals for the Fifth Circuit ruled in a Texas case that minority groups cannot combine claims of vote dilution.

This week’s ruling, which limits the Voting Rights Act, directly affects the three states under the jurisdiction of the U.S. Court of Appeals for the Fifth Circuit, but its impact could be felt nationwide.

A federal appeals court has further restricted the 1965 Voting Rights Act, ruling that separate minority groups cannot unite to claim that a political map has been designed to dilute their collective voting power.

In a 12-to-6 decision on Thursday, the full Fifth Circuit Court of Appeals overturned nearly 40 years of legal precedent. The ruling also reversed decisions by both a three-judge panel from the same court and an earlier federal district court. Although the ruling applies only in Louisiana, Mississippi, and Texas—states under the court’s jurisdiction—it addresses a common issue in redistricting and has broader national significance.

The case centers on a district map for county commissioners in Galveston County, Texas. Mark Henry, the county judge who leads the Republican-controlled commissioner’s court responsible for drawing the map, hailed the decision as “a great win for the rule of law and the Constitution.” Henry is a defendant in the lawsuit.

The plaintiffs, including the Justice Department and groups like the N.A.A.C.P. and the League of United Latin American Citizens (LULAC), have not yet decided whether to appeal to the U.S. Supreme Court. However, the ruling leaves room for further legal challenges, as it directs the district court to reassess two other claims: that the county intentionally discriminated against minority voters and engaged in illegal racial gerrymandering. This means the map could still be ruled unlawful on those grounds.

“We still have a lifeline,” said Robert Quintero, president of the Galveston chapter of LULAC. “We won in this court before, and we hope the judge will apply the same wisdom he showed in the first ruling.”

Mark P. Gaber, a lawyer representing the Black and Latino voters involved in the case and part of the Washington-based Campaign Legal Center, stated that their claim of vote dilution remains robust.

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