The Legislation, House Bill 934, was authored by Republican State Representative Daryl Metcalfe. According to Metcalfe, it was based on Indiana's Voter ID law which was upheld as Constitutional by the U.S. Supreme Court. Metcalfe goes on to identify four types of fraud which would be prevented by the bill: impersonation at the polls, fictitious registrations, double voting, and voting by illegal aliens.
Critics have said this doesn't happen. A few videos for their consideration: