The Supreme Court ruling last month freed a number of states with a history of discrimination, mostly in the South, of the requirement to get advance federal permission in order to make changes to their election laws.

Within hours, Texas officials said that they would begin enforcing a strict photo identification requirement for voters, which had been blocked by a federal court on the ground that it would disproportionately affect black and Hispanic voters. In Mississippi and Alabama, which had passed their own voter identification laws but had not received federal approval for them, state officials said that they were moving to begin enforcing the laws.

The next flash point over voting laws will most likely be in North Carolina, where several voting bills had languished there this year as the Republicans who control the Legislature awaited the Supreme Court ruling on the Voting Rights Act of 1965, which had covered many counties in the state. After the ruling, some Republican lawmakers said that they would move as soon as next week to pass a bill requiring voters to present photo identification at the polls. And some Republicans there are considering cutting back on the number of early voting days in the state, which were especially popular among Democrats and black voters during the 2012 presidential election.