Daniel Strauss makes a point that can't be repeated enough regarding voter fraud:
A few years ago the Brennan Center for Justice, at New York University, undertook an exhaustive analysis of voter fraud allegations -- everything from reports that people were voting twice to stories of dead people casting ballots. The vast majority of allegations turned out to be baseless and, in a 2007 report, the Center's Justin Levin wrote that "It's more likely that an individual will be struck by lightning than that he will impersonate another voter at the polls." More recently, in a 2010 book called The Myth of Voter Fraud, Barnard political science professor Lorraine Minnite did her own analysis based on state government records. She reached the same conclusion. According to Minnite, between 2002 and 2005 there was only one case of voter registration fraud and five cases of people voting twice. That’s a total of six cases within a three year span.
You needn't trust the dirty libs and their data here. The Bush administration had control of the Justice Department for eight years and was unable to find more than a few scattered cases, none of which involved large-scale plots to influence an election. Although I suppose you could continue to believe that the lack of prosecutions just proves the depth and effectiveness of the conspiracy, and that the people capable of such profound subterfuge were simply outwitted by some guy in a pimp costume. "Voter fraud" allegations are a mere pretext for justifying laws and practices that are more likely to disenfranchise Democratic-leaning constituencies -- the fact that myths about stolen elections have persisted in the absence of any evidence supporting them is a testament to the effectiveness of the Republican Noise Machine.