Judge Ramos acknowledged the difficulty of pinning down the Legislature’s motives. She wrote of considering “all available direct and circumstantial evidence of intent” rather than trying to “discern the motivations of particular legislators.” The judge highlighted attempts by Democrats to blunt the racial impact of the law, known as Senate Bill 14, through amendments that were ultimately rejected, including allowing additional types of photo identification. “Many categories of acceptable photo IDs permitted by other states were omitted from the Texas bill,” she wrote.

Kristen Clarke, the president and executive director of the Lawyers’ Committee for Civil Rights Under Law, which represented some of the plaintiffs, said the ruling on Monday marked the fifth time that a court found that the law had a discriminatory purpose or effect.

Judge Ramos’s decision, she said, “should sound the death knell for burdensome voter ID requirements in Texas and across the country.”

For decades, Texas and several other mostly Southern states with a history of discrimination had been required to seek federal approval before making changes to their voting laws. But the states were freed from that requirement in 2013, after a Supreme Court decision that invalidated key provisions of the Voting Rights Act.

The finding of intentional discrimination could once again put Texas under federal supervision. It would be the first state brought back into so-called preclearance since the Supreme Court’s 2013 ruling. Judge Ramos did not address whether she would order Texas to undergo federal oversight, but will examine the issue during the next stage of the case.

The law was passed by the Legislature and signed by then-Gov. Rick Perry in 2011, but took effect in 2013. It required voters to show a driver’s license, passport or other government-issued photo ID before casting a ballot. It was previously found by the appellate court to have a discriminatory effect on black and Hispanic voters, many of whom lacked government-issued photo identification, and as a result was softened for the November 2016 election.

Numerous Democratic lawmakers, voters, civil rights organizations and black and Hispanic groups sued, arguing that Republican legislators steamrollered the bill through the State House and Senate. They said legislators departed from procedural norms in passing the law, including classifying it as emergency legislation, cutting debate short and bypassing the ordinary committee process in both chambers.