Anyone who hopes to vote in Texas this year needs an approved form of government-issued photo ID. Concealed handgun licences count; student IDs do not. The state’s Republican lawmakers introduced this requirement in 2011, arguing that it would prevent fraud and ensure the integrity of elections. They passed it over the objections of Democrats, who maintained that voter-ID laws are merely a cynical way to suppress turnout—especially among African-Americans, Hispanics and poor people—and who have continued to fight the law in court on that basis. The legal wrangling has thus far been inconclusive, and confusing. Texas was finally able to implement its voter-ID law in time for this year’s primaries, as a result of Shelby County v Holder, the Supreme Court decision in 2013 that struck down part of the Voting Rights Act (meaning that a number of states with a history of discriminating against minority voters, including Texas, no longer need the federal government to clear new voting restrictions). But then on October 8th a federal judge struck down Texas’s law on its own merits, ruling that insofar as some 600,000 registered voters in the state lacked the relevant forms of ID—about 4.5% of the state’s registered voters—the requirement was tantamount to a “poll tax.” On October 18th, though, with the early voting period set to begin about 48 hours later, the Supreme Court allowed the law to remain in place for the general election. Debate over the law promises to continue. But this year, for the first time, Texans will finally be able to assess its impact in practice.