Here’s what he’s come up with in his latest column, that I linked to earlier this morning:

One reason for such large public support is that the potential for fraud is real. Many people don’t trust electronic voting machines. And in recent years Democratic candidates have leveled credible accusations of voter fraud in mayoral races in Detroit, East Chicago, Ind., and St. Louis.
Last week, election officials in San Antonio, Texas determined that 330 people on their voter rolls weren’t citizens and that up to 41 of them may have voted illegally, some repeatedly. In 2004, San Antonio was the scene of a bitter dispute in which Democratic Rep. Ciro Rodriguez charged his primary opponent with voter fraud.
In Florida, a felon named Ben Miller was arrested last week for illegally voting in every state election over a period of 16 years. The Palm Beach Post discovered that in Florida’s 2000 infamous presidential recount, 5,643 voters’ names perfectly matched the names of convicted felons. They should have been disqualified but were allowed to vote anyway. “These illegal voters almost certainly influenced the down-to-the-wire presidential election,” the Post reported. By contrast, only 1,100 people were incorrectly labeled as felons by election officials, the Post estimated.

Others have pointed out the problems with most of these allegations (see, for example, here and here), and note that the allegations on electronic voting and felon voting have nothing at all to do with voter id.