The law allows the state to send address confirmation notices to voters who have not engaged in voter activity for two years. If a voter returns the notice through prepaid mail, or responds through the Internet, the information is updated. If the notice is ignored and the voter fails to update a registration over the next four years, the registration is canceled.
The ruling concerning the battleground state comes as the country gears up for elections this fall. Six other states have similar laws, and the ruling could encourage others to pass similar laws.
"We have no authority to second-guess Congress or to decide whether Ohio's supplemental Process is the ideal method for keeping its voting rolls up to date," the majority opinion by Justice Samuel Alito states. "The only question before us is whether it violates federal law."