News 21, a national investigative reporting project funded by the Carnegie Corporation of New York and the John S. and James L. Knight Foundation, found 150 alleged cases of double voting, 56 cases of noncitizens voting, and 10 cases of voter impersonation across all elections from 2000 to 2011. Many of these allegations never led to charges, while others were acquitted or dismissed.
Justin Levitt, a professor at Loyola Law School and an expert on voter fraud, found an even smaller number: 31 credible incidents out of more than 1 billion votes cast from 2000 to 2014.
Put it in another way: More people are struck by lightning or attacked by sharks than are accused of voter fraud.
When voter fraud does occur, it’s not always intentional. Multiple studies have traced known cases not to willful deception but to clerical errors or confusion.In 2007, The New York Times reported:
Five years after the Bush administration began a crackdown on voter fraud, the Justice Department has turned up virtually no evidence of any organized effort to skew federal elections, according to court records and interviews.
Although Republican activists have repeatedly said fraud is so widespread that it has corrupted the political process and, possibly, cost the party election victories, about 120 people have been charged and 86 convicted as of last year.
Most of those charged have been Democrats, voting records show. Many of those charged by the Justice Department appear to have mistakenly filled out registration forms or misunderstood eligibility rules, a review of court records and interviews with prosecutors and defense lawyers show.
In Miami, an assistant United States attorney said many cases there involved what were apparently mistakes by immigrants, not fraud.