In a 147-page opinion issued in the fall of 2014 after a two-week trial, a district court judge, Nelva Gonzales Ramos, said the law “creates an unconstitutional burden on the right to vote” and blocked its enforcement.

She noted the lack of evidence that voter fraud was a threat and cited expert testimony that about 600,000 Texans, mainly poor, black and Hispanic, lacked the newly required IDs and often faced obstacles in obtaining them.

Texas appealed her decision to the Fifth Circuit, which, without deciding the issues, put the identification law back into effect, saying it would be too disruptive to change the rules so close to Election Day.

The appeals panel said Wednesday that because illegal intent to discriminate had not been established — in passing the law, legislators declared an interest in preventing voter fraud — the district court in Texas should seek ways to alter the voter law short of overturning it entirely. The state could, for example, reinstate the acceptance at the polls of certain forms of identification that may be more easily available.

Apparently referring to that part of the ruling, the Texas attorney general, Ken Paxton, said in a statement Wednesday that the decision was a “victory on the fundamental question of Texas’ right to protect the integrity of our elections,” adding that “our state’s common sense voter ID law remains in effect.”

But civil rights advocates focused on the court’s decision to uphold Judge Ramos’s finding that the ID law had a discriminatory effect, thus violating Section 2 of the federal Voting Rights Act.

The appeals court said it did not need to decide whether the law also violated provisions of the Constitution, like the 14th Amendment, and it rejected Judge Ramos’s finding that it amounted to an illegal poll tax.