From: David Boone
The only time to guarantee there is no voter fraud is before the ballots go into the box. Once a vote is cast, no one knows, nor should they know, who voted for whom. The recounts in Minnesota over the last several cycles have proved nothing about whether the votes were legally cast, only that the tallies of the actual ballots were accurate.
Two states, Indiana and Georgia, have held elections under new picture ID laws. In both cases they have seen a boost in voter participation overall and particularly among minorities. The conclusion seems to be the more the confidence in the system, the better the turnout.