The Supreme Court appeared divided along familiar lines Wednesday as the justices considered how states such as Ohio can remove voters from registration rolls without violating federal laws to protect people who simply choose not to vote.

The case could affect this year’s elections and how states determine who remains on the lists of eligible voters. The justices will decide the case before their term concludes at the end of June, but did little Wednesday to foreshadow how they ultimately would rule.

The liberal justices, and particularly Justice Sonia Sotomayor, vigorously questioned an attorney for Ohio about the state process, which uses a list of people who haven’t voted in recent elections to trigger steps that would clean up voter registration rolls.

Sotomayor pointed out that there are dozens of other ways to verify that a voter has changed addresses or is otherwise ineligible to vote. Congress specifically said that it is a right to not vote, which should not be used to remove someone from the registration rolls, she said.

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The state’s use of failure to vote as a trigger to remove them from rolls disproportionately affects people in cities where minorities live; the homeless; those who work long hours; or those who don’t want to wait in long voting lines, Sotomayor said.

“I have to give the meaning, the words that Congress said, don’t use the failure to vote as a result that results in someone being disenfranchised,” she said.

Eric Murphy, the Ohio solicitor general, responded that outlawing the Buckeye State’s use of failure to vote as a trigger would prevent any state from taking the same reason into account when determining if someone was still eligible to vote.

Justice Samuel A. Alito Jr., a conservative, gave voice to those concerns as well. He expressed doubt that federal laws — a 1993 law, better known as the “motor voter” law, and a 2002 statute called the Help America Vote Act — wouldn’t allow states to use failure to vote as a reason to question whether someone should be removed.

“You think that if somebody hasn’t voted for 20 years, that doesn’t raise an inference that the person has moved or died?” Alito said.

Paul Smith, the attorney for voting rights groups who challenged the Ohio law, told the justices that more than half of the state’s voters don’t vote every two years, which triggers the state to send them a card that asks them to either verify their address or vote in an election in the next four years. Seventy percent of people don’t return those cards, he said.

“You’re just going to end up with a lot of false positives in the end, and that is, in fact, how the system is operating,” Smith said. “It finds a lot of people that supposedly have moved who simply haven’t moved.”

Justices Neil Gorsuch and Clarence Thomas did not ask any questions Wednesday.

The U.S. Court of Appeals for the 6th Circuit had sided with the challengers and issued an order halting the law during the 2016 election.

The case is Husted v. A. Philip Randolph Institute, Docket No. 16-980.