WASHINGTON — In a 5-4 ruling, the U.S. Supreme Court gave Ohio a victory Monday in a fight over the state's method for removing people from the voter rolls, a practice that civil rights groups said discourages minority turnout.

At least a dozen other politically conservative states said they would adopt a similar practice if Ohio prevailed, as a way of keeping their voter registration lists accurate and up to date.

Prof. Rick Hasen, an election law expert at the University of California, Irvine, predicted that a win for Ohio would escalate voting wars between the political parties.

"You'll see more red states making it easier to drop people from the voter registration rolls," he said.

President Donald Trump, who is in Singapore for the nuclear summit, cheered the decision on Monday night.

Just won big Supreme Court decision on Voting! Great News! — Donald J. Trump (@realDonaldTrump) June 12, 2018

All states have procedures for removing from their registration lists the names of people who have moved and are therefore no longer eligible to vote in a given precinct. The issue before the Supreme Court was whether a voter's decision to sit out a certain number of elections could be the trigger for that effort.

Justice Samuel Alito, who wrote the majority opinion, said the court's job was not "to decide whether Ohio’s supplemental process is the ideal method for keeping its voting rolls up to date. The only question before us is whether it violates federal law. It does not."

Ohio election officials send notices to anyone who fails to cast a ballot during a two-year period. People who do not respond and don't vote over the next four years, including in two more federal elections, are dropped from the list of registered voters.

Larry Harmon sits in his home in Kent, Ohio, on Aug. 4, 2017. Harmon was removed from the voting rolls after not voting in the last election. Maddie McGarvey / for NBC News

That's what happened to Larry Harmon, a U.S. Navy veteran and software engineer who was turned away from his polling place in 2015 when he found out he wasn't on the list. "I looked and I looked. And I saw my son's name, but I didn't see my name." So he joined a civil rights group in suing the state. Ohio said he was sent a notice, but he said he didn't get it.

A federal appeals court ruled against the state, concluding that roughly 7,500 Ohio voters — in a state that's perennially a presidential battleground — were wrongly purged from the list in the 2016 election.

Opponents of Ohio's system, led by the A. Philip Randolph Institute, said it violated the National Voter Registration Act, which specifies that voters can be purged from the rolls only if they ask, move, are convicted of a felony, become mentally incapacitated, or die. More than half the voters in Ohio fail to cast a ballot over a two-year period, the group said, and those who receive the state's notices simply throw them away.

"The Supreme Court got this one wrong. The right to vote is not 'use it or lose it,'" said Chris Carson, president of the League of Women Voters of the United States. "This decision will fuel the fire of voter suppressors across the country who want to make sure their chosen candidates win reelection, no matter what the voters say."

Justice Stephen Breyer authored the dissent, which was joined by liberal justices Elena Kagan, Ruth Bader Ginsburg and Sonia Sotomayor, who also wrote a separate — and scathing — dissent.

Sotomayor scolded the court's majority for ignoring "the history of voter suppression against which the NVRA [National Voter Registration Act] was enacted and upholds a program that appears to further the very disenfranchisement of minority and low-income voters that Congress set out to eradicate."

"Communities that are disproportionately affected by unnecessarily harsh registration laws should not tolerate efforts to marginalize their influence in the political process, nor should allies who recognize blatant unfairness stand idly by," Sotomayor added.

The Ohio Democratic Party issuing a statement condemning the ruling.

"Today’s split decision from the U.S. Supreme Court will unfortunately empower Republican officials across the country to continue making it harder for American citizens to vote," Chairman David Pepper said, adding that "voting rights are on the ballot with this November's elections."

The Obama Justice Department supported the challengers in the early stages of the court fight, arguing that the mere exercise of the right not to vote cannot be the basis for removing a name from the voter rolls. But the Trump administration switched sides and supported Ohio, saying in a court brief that the state's system strikes a balance between "on the one hand dramatically increasing the number of voters on the voter rolls but, on the other, giving states the flexibility they need to manage the issues that arise when you have over-inflated voter rolls."