From the Harvard Law and Policy Review
Since the passage of the Help America Vote Act (HAVA) in 2002, requiring people to present identification to vote has become one of the most controversial and divisive issues in election reform. HAVA necessitates, among other things, that members of a small group of people--new voters registering by mail--establish their identity in one of many ways. While about half of the states in the country today apply just that requirement, many states have used the HAVA identification provision to justify additional, more stringent measures. At present, twenty-four states require all voters to present identification when casting a ballot in person.
