"We have seen the most aggressive voter purge…over 2 million Ohio voters purged from the roll. Much purging was illegal purging for infrequent voting," Clyde said in a telephone news conference hosted by the Center for American Progress, a think tank in Washington, DC.
"The voters who were illegally purged will be able to vote, but they will have to use a provisional ballot," she added.
A provisional ballot is cast if a voter's registration has incorrect or outdated information such as a misspelled name or an incorrect address. In Ohio and most other US states, a provisional ballot is not counted until after the election, as long as the individual is deemed eligible to vote.
US elections for president, seats in Congress and numerous state and local offices will take place November 8.