Under the OH regime, voters who don't vote in a two-year federal election cycle are sent mailers asking that they confirm they still reside where they are registered to vote.
Justice Samuel Alito, writing the majority opinion, says OH is complying with the 1993 National Voter Registration Act by maintaining its voter lists.
Justice Samuel Alito said for the court that OH is complying with the 1993 National Voter Registration Act. He is joined by his four conservative colleagues.
"The Supreme Court has just given a stamp of approval to voter suppression", said Liz Kennedy, senior director of Democracy and Government Reform at the Center for American Progress.
OH is one of six states that uses the so-called supplemental process - and the only one that begins sending letters to voters if they go just two years without voting.
So the state asks people who haven't voted in two years to confirm their eligibility. If the voters don't respond to the mailers, and don't engage in any voter activity - which includes, voting, updating one's voter registration info, or participating in voter petitions - in the next two federal election cycles, they are removed from the rolls. If they do, or if they show up to vote over the next four years, voters remain registered.
But U.S. Solicitor General Noel Francisco - whose office changed sides in the case after Trump was elected - said OH had the right to streamline "over-inflated" and "bloated" voter registration rolls.
The state argued that the policy was needed to keep voting rolls current, clearing out people who have moved away or died.
Justice Stephen Breyer, writing in dissent, said the 1993 law prohibits removing someone from the voting rolls "by reason of the person's failure to vote".
"We are now only 5 months from our next federal election and any rush now to remove a backlog of up to 589,000 voters that he has marked for purging will be extremely disruptive and unfair to OH voters", Clyde wrote.
The Ohio program follows this to the letter.That's because minorities, young people and those with lower incomes are more likely to be disenfranchised by the state's policy. The court's decision essentially endorses "the very purging that Congress expressly sought to protect against", Sotomayor wrote. Most of the states that backed OH have Republican governors or legislatures; most of those opposed are governed by Democrats.
Civil rights groups have fought against the voting measure, arguing that it discourages minority turnout. A federal appeals court had blocked the procedure for 2016, letting 7,500 state residents cast ballots even though they'd previously been struck from the rolls.
Husted called the decision "a victory for electoral integrity".
Republican President Donald Trump's administration backed OH, reversing the stance taken by Democratic former President Barack Obama's administration against the policy, and welcomed the ruling. A three-judge panel on that court had ruled 2-1 that Ohio's practice was illegal.