The Trump administration plans to abandon the federal government's longstanding opposition to a key portion of Texas' toughest-in-the-nation voter ID law, a U.S. Justice Department spokesman said Monday.

It's a dramatic break from the agency under President Barack Obama, which spent years arguing that the 2011 voter ID law that Texas' Republican-controlled Legislature passed was intended to disenfranchise poor and minority voters.

Danielle Lang of the Washington-based Campaign Legal Center called the decision an "extraordinary disappointment."

"It's a complete 180," said Lang, the center's deputy director of voting rights. "We can't make heads or tails of any factual reason for the change. There has been no new evidence that's come to light."

The law requires voters to show one of seven forms of state-approved photo identification -- gun permits are acceptable but college IDs are not. Voting rights activists sued, and the case returns to court Tuesday in Corpus Christi, Texas, before U.S. District Judge Nelva Gonzales Ramos.

Justice Department spokesman Mark Abueg said the agency was preparing a brief detailing its rationale for the move. He said that although the Justice Department will no longer argue that the law was intended to discriminate against minorities, it doesn't plan to withdraw from a portion of the lawsuit that argues that the law had the effect of discriminating against them.

A federal appeals court last year ruled on effect, deciding that the Texas law discriminated against minorities and the poor and ordering changes ahead of the November election.

The U.S. Supreme Court last month declined a Texas appeal that sought to restore the law, but Chief Justice John Roberts left the door open for another appeal at a later time.

Along with Texas, the Obama-led Justice Department launched a high-profile legal challenge against North Carolina's voter ID law, arguing that its requirements were unnecessary and unconstitutional.

North Carolina's top Democrats recently asked the U.S. Supreme Court to dismiss an effort to restore the law, which had been struck down as unconstitutional.

Republican-led legislatures around the country have in recent years rushed to pass restrictions on voting in an effort to prevent fraud at the ballot box, despite any evidence that it's a widespread problem.

Under Obama, the Justice Department sought to contest such measures, but the Trump administration's change in strategy could empower other conservative-controlled states to follow Texas' lead and tighten their voter ID rules.

Trump has consistently touted unsubstantiated claims of voter fraud and has praised laws requiring ballot box photo identification.

Attorney General Jeff Sessions repeatedly sounded alarms over voting fraud and intimidation as a U.S. senator and challenged Justice Department attorneys over whether they were pursuing it aggressively enough. As a U.S. attorney in Alabama in the 1980s, he prosecuted three civil rights activists on charges of tampering with ballots.

The three defendants were acquitted in a matter of hours. And during his confirmation hearing last month, Sessions defended laws requiring voters to show picture identification at the polls: "I think voter ID laws, properly drafted, are OK."

Wendy Weiser, director of the democracy program at the Brennan Center for Justice, said it was disappointing that the Justice Department would change its legal position.

"The more vigorously the Department of Justice pursues illegal discrimination when it happens, the more deterrent an effect it has," she said.

"When they pull back from vigorous enforcement, it may have an unfortunate and pernicious effect of sending a green light to states that there's going to be less policing" of discriminatory laws.