The survey asked those who voted by mail in the 2020 election if they filled out a ballot "in part or in full, on behalf of a friend or family member, such as a spouse or child?" to which 21 percent said they had done so.

Though many states allow voters to receive assistance while voting, the Heartland Institute notes, filling out ballots on behalf of another person is illegal across the United States.

In addition, 17 percent of mail-in voters in the 2020 election said they cast a ballot in a state where they were no longer a permanent resident — a violation of federal election law. Another 17 percent of mail-in voters said they signed a ballot on behalf of someone else, also a violation of election law.