Here's what Jon Husted, our Republican Secretary of State, said about 2012 voter fraud in a report earlier this year.
http://www.sos.state.oh.us/SOS/mediaCenter/2013/2013-05-23.aspx
Highlights: 625 recorded cases of "voting irregularities", of which also include reports alleging voter suppression. Of these only 135, including those referred by the SoS, were referred to county prosecutors for potential charges. Then apparently 490 suspected cases are certifiably unprovable. Nothing about them has evidence backing a an indictment. So two people named 'Bill Smith' vote in the same precinct. One is "Bill Smith, Sr.", and the other is "Bill Smith, Jr." -- father and son. Maybe there are two cases of people named "Juanita Garcia" voting in the same precinct. Maybe they are two different people. Someone proved to have died between casting an absentee ballot and the election? It happens all the time.
So some college student from Cleveland is registered both in Cleveland and Columbus and votes in Columbus where he is a student at Ohio State? OK -- that happens, and the question is whether one can prevent him from voting in two places. In most states, a new registration invalidates an earlier registration with no consequences.
Multiple registrations? It's up to election officials to ensure that only one of those registrations is legitimate.
Someone might register before achieving full citizenship on the assumption that citizenship at the time of the election is good enough -- just as it is possible for someone to register at age 17 so long as one turns 18 on or before Election Day. We should all know about that.
Seeming irregularities often prove innocuous or to be understandable errors which probably wash out. Most vote fraud is done by administrators of elections.
Lack of evidence mandates acquittal if a charge is made; such is the assumption behind the presumption of innocence that distinguishes the legal system of the US from that of the old Soviet Union.
Voter fraud just isn;t worth the risk.
Good enough for me. It's time for Republicans to quit being sore losers about elections that they fail to win in the absence of dirty tricks. Maybe some people want to redefine the electorate to their political advantage. It's been done, as in Apartheid-era South Africa.