Critics charge that the voter records are rife with irregularities. But Minnesota's DFL Secretary of State said the attacks are coming primarily from a conservative group with ties to his Republican predecessor.
The left-leaning advocacy group ACORN, which has signed up 43,000 voters in the state, has been at the center of the controversy.
In response to Republican allegations of sloppy voter-registration practices, local canvassers rallied in defense of their work last week in North Minneapolis.
The gathering drew some of the metro area's most liberal politicians, including St. Paul City Council Member Dave Thune and Congressman Keith Ellison, both DFLers.
"We don't need to criticize ACORN," Ellison said. "We need to get some more acorns around here, and put them in the ground and have them grow up like a mighty tree!"
Conventional wisdom says Democrats do better when more people head to the polls, while Republicans typically benefit from low voter turnout.
A conservative group called Minnesota Majority has been spreading the word of irregularities in the state's voter rolls.
"We've found instances where there appears to be exact duplicate records -- same names, same birth year, same telephone number, same address," said Jeff Davis, president of Minnesota Majority.
Davis said a number of registered voters appeared to be minors when they signed up. And he says 29,000 people on the voter rolls listed addresses where nobody actually lives.
He's urging the Secretary of State's office to investigate the irregularities. Until that happens, his group is doing its own sleuthing by calling up people whose voter data files seem "suspicious."
But, just because someone is listed twice in the voter rolls, doesn't mean people are trying to vote twice. Davis said that's not the point.
"There shouldn't be duplicate entries in the voter file," Davis said. "We're not necessarily saying these are all instances of voter fraud. We're basically saying there's inconsistencies in the file, which open it up to the possibility of a lot of different things happening." Members of Davis' group have vigorously fought against gay marriage and illegal immigration. He said it was only when they were coordinating mass mailings that they happened to notice discrepancies in the Secretary of State's voter roster, and picked it up as a separate cause.
But his critics say this argument doesn't hold much water in Minnesota.
"All over the country, we're recognized as the best and cleanest system," said Minnesota Secretary of State Mark Ritchie.
Ritchie, a DFLer, said officials cross-check voter records with drivers licenses, Social Security records, death records and court lists of convicted felons. The idea is to verify that a person is real, and to flag individuals who have not obtained or who have lost their right to vote.
While the system may not be perfect, Ritchie said there's no evidence of widespread abuse.
Ritchie found that in the 2006 election, when he was elected, as many as three people who were not U.S. citizens registered to vote and possibly did vote. That's out of roughly 3 million registered voters.
"That would be 0.000001 of a percent," Ritchie said.
Ritchie notes that Davis' group has ties to Mary Kiffmeyer, his Republican predecessor. She's also board adviser to another group, the Minnesota Voters Alliance, which supports requiring photo identification at the polls.
Ritchie said the recent furor over voter records has reached a new high in Minnesota.
"There is a new level of desperateness, a new level of intensity to the process that's saying, 'This can't be right. There must be all these people illegally voting,'" Ritchie said. "It's to create a story to explain a political climate. It's to create a cloud over an election so people don't accept the outcome."
Ritchie said some of the glitches in the database correct themselves. For example, one of the voters Minnesota Majority called last week to investigate had registered at two addresses.
Turns out, the voter had moved into a new house. Ritchie said once the voter shows up at his new polling precinct, election officials will know his correct address. The system will be cleaned, and the duplicate entry purged, but that happens after the election.