The American Civil Liberties Union sued Iowa's top election official, Secretary of State Paul Pate, on behalf of four Iowa voters, alleging that his office violated their right to vote by instructing election workers to question ballots that might have been naturalized citizens. Pate's office is understood to have previously provided county auditors with a list of 2,022 people who had reported being non-citizens but then registered to vote. Because these people may have become naturalized citizens during this time, Pate's office advised county election officials to challenge their ballots and ask them to provide proof of citizenship or switch to a provisional ballot.