The U.S. Supreme Court will decide whether Ohio wrongfully purged eligible voters from the state's registration list.
The justices on Tuesday agreed to hear an appeal from state officials defending the process against challengers who say it's illegal.
Civil liberties groups had challenged the state's program for removing thousands of people from voter rolls based on their failure to vote in recent elections. A federal appeals court ruled last year that the process violates the National Voter Registration Act.
Ohio officials argue that the process used by Ohio for more than 20 years is constitutional and fully complies with state and federal laws.
Groups challenging the practice said Ohio was unfairly disenfranchising eligible Ohio voters.