Thousands of voters in the capital city of Madison, Wisconsin, received duplicate absentee ballots in the mail recently, a "blunder" officials attribute to a "human error" while at least one area Republican suggested more nefarious motives.

Late last week, the Madison clerk's office sent out the duplicate ballots after officials attempting to merge two separate data files apparently accidentally copied them instead, deputy clerk Jim Verbick told WKOW.

According to city spokesperson Dylan Brogan, the clerk's office already has several "fail-safe" measures in place to prevent voters from casting more than one ballot.

The city is contacting each individual who received a duplicate ballot and instructing voters to destroy one of them. Should they miss or ignore the message, a unique barcode affiliated with the absentee ballot material sent to voters should prevent them from casting more than one ballot each.

Finally, Brogan explained to the AP, registered voters who have cast absentee ballots are marked in the system. If they attempt to cast another ballot, the records will reflect that the voter is ineligible to cast another one.

"This was a mistake," Brogan said. "The clerk’s office moved to rectify it as quickly as possible."

'Your office’s ... persistent efforts to scrub your website, and your personal links to a controversial "Zuckerbucks"-financed group, will only fuel growing public doubts about your ability and willingness to administer a free and fair election.'

While officials like Verbick and Brogan rushed out to insist that the threat of possible voting shenanigans had been contained, at least one Republican is not satisfied with their explanations.

U.S. Rep. Tom Tiffany, an ardent Trump supporter whose district does not include Madison, demanded further answers since this apparent mistake occurred in one of the most heavily Democratic areas of the state. Plus, city officials keep changing their story, he said.

Citing Verbick, Tiffany claimed in a letter addressed to Madison clerk Maribeth Witzel-Behl that absentee ballots themselves actually do not have a unique barcode but only the return envelope, casting doubt on whether a second ballot from the same voter would be rejected. He tweeted an image of an absentee ballot to buttress his claim.

Moreover, officials initially claimed that the issue affected "up to 2,000" voters in only one ward, but just 24 hours later they revised those numbers to at least 2,215 voters in at least 10 wards. As such, Tiffany said, some affected voters may not have received the message from the city, especially since "the Clerk’s office was not yet even fully aware of how widespread the 'error' was."

Tiffany has since demanded that a third party investigate the incident, but so far, city officials have rebuffed those demands.

"Your office’s continued resistance to allowing for a third-party investigation of what transpired, persistent efforts to scrub your website, and your personal links to a controversial 'Zuckerbucks'-financed group, will only fuel growing public doubts about your ability and willingness to administer a free and fair election," Tiffany wrote.

Tiffany also accused the city of having a "history of controversial and legally dubious election practices."

In response to that accusation, Verbick told WKOW, "No comment."

Verbick did, however, respond to Tiffany's letter in general: "I would just say that [the clerk's office] is very transparent about anything we do with elections, and I would just leave it at that."

In response to questions about the exact number of duplicate ballots and wards involved, Brogan confirmed to Blaze News that "2,215 duplicate absentee ballots were issued to voters" located in 10 wards: "1, 4, 5, 8, 9, 10, 11, 12, 14, [and] 15."

While any instance of voting irregularities is a problem, this issue is particularly significant in Wisconsin, a swing state that Joe Biden officially carried by fewer than 21,000 votes four years ago. In 2016, Trump won Wisconsin by about 28,000.

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