We are, apparently, already beginning to see the effects of the recent Supreme Court decision that upheld an Indiana law requiring voters to produce a photo I.D. at the polls. On Monday, the New York Times reported on a measure currently being considered in Missouri that would go even further than the disputed Indiana law.
Missouri legislators are reportedly expected to support a proposed constitutional amendment that, if passed, would mean state residents would have to show proof of citizenship when they go to vote. That means a birth certificate, a passport or naturalization papers. According to the Times, at least 19 state legislatures are considering something like this, but "only in Missouri does the requirement have a chance of taking effect before the presidential election." If passed by the Legislature, the amendment would still have to go to the voters themselves for approval.
There seems to be little statistical basis for the Republican fixation on voter fraud. The few studies that have been done show fraud to be insignificant to the outcome of elections; it has been measured at levels as low as .0004 percent (PDF) of all ballots cast. Loraine Minnite, an assistant professor of political science at Barnard College, conducted a study of elections from 1992 to 2002 for Demos, a London- and New York-based public-policy think tank. Her analysis of the numbers showed that "the incidence of election fraud in the United States is low and that fraud has had a minimal impact on electoral outcomes."