Representative Trey Martinez Fischer, the chairman of the Mexican-American Legislative Caucus in the Texas House of Representatives, flew to Washington this week to persuade a panel of federal judges to invalidate a requirement that voters must have an ID card. His trip was less arduous than the one some residents would have to endure to get a government-issued photo ID.

“In West Texas, some people would have a 200-mile round-trip drive” to the nearest state office to get a card, he testified, according to The Dallas Morning News. More than a quarter of the state’s counties don’t even have an office to get a driver’s license or voter card. Lines at the San Antonio motor vehicles offices are often more than two hours long, he said.

Texas is one of 10 Republican-controlled states that have imposed a government ID requirement to vote, purportedly to reduce fraud but actually to dissuade poor and minority voters who tend to vote Democratic. (Seven other states have passed slightly less-restrictive rules.) In most cases the federal government can do little to resist this incursion on voting rights, because the Supreme Court upheld ID requirements in 2008. But Texas is different. It is covered by the Voting Rights Act of 1965, which allows the Justice Department to disapprove of any change in voting procedures in areas with a history of discrimination.

That’s exactly what the department did in March, saying the law imposes a huge disadvantage on Hispanic voters, who lack a government ID, like a driver’s license or gun permit, at a far higher rate than the general population. Texas sued, and a trial began Monday.