Wisconsin Congresswoman Tammy Baldwin (D) is asking U.S. Attorney General Eric Holder to begin an investigation into the handling of votes cast in the state's Waukesha County.

Republican county clerk Kathy Nickolaus claimed last week that she had found thousands of unreported votes, which gave incumbent David Prosser a more than 7,000 vote lead over JoAnne Kloppenburg.

"Following this week’s election for the Wisconsin Supreme Court, numerous constituents have contacted me expressing serious doubt that this election was a free and fair one," Baldwin wrote in her letter to Holder. "They fear, as I do, that political interests are manipulating the results."

"To ensure that the April 5th election for Wisconsin Supreme Court Justice is free, fair, and transparent, and to uphold faith in our democracy for ourselves and future generations, I ask for your immediate assistance in investigating these election inconsistencies in Wisconsin. Specifically, I urge you to immediately assign the Justice Department Public Integrity Section, which oversees the federal prosecution of election crimes, to investigate the questionable handling of vote records in Waukesha County, Wisconsin," she concluded.

Justice Department spokesman Wyn Hornbuckle told Green Bay Press Gazette over the weekend that the department would review Baldwin's request.

Nickolaus, a Republican activist, had faced heavy criticism previously for keeping election results on an antiquated personal computer.

She blamed "human error" Thursday night after revealing the votes that gave Prosser the lead.

"It's important to stress this isn’t a case of extra votes or extra ballots being found," she said. "This is error, which I apologize for, which is common in this process."

Kloppenburg issued a statement Thursday evening saying should would be requesting all relevant records regarding the vote fiasco.

"Wisconsin voters as well as the Kloppenburg for Justice Campaign deserve a full explanation of how and why these 14,000 votes from an entire City were missed," she said.

"We are confident that election officials in Waukesha County will fulfill these requests as quickly as possible so that both our campaign and the people of Wisconsin can fully understand what happened and why," Kloppenburg added.

Prosser said in a statement that he had been "encouraged" by the developments.

"Our confidence is high, and we will continue to monitor with optimism, and believe that the positive results will hold," Prosser said. "We've always maintained faith in the voters and trust the election officials involved in the canvasing will reaffirm the lead we've taken."

Huffington Post senior polling editor Mark Blumenthal believes that the "most convincing evidence so far that human error explains the initial omission" was that the Brookfield Patch reported on election night a vote total for the city of Brookfield that exactly matches Nickolaus' discovered votes.

While neither of the candidates have officially called for a recount, both have hired high-profile attorneys with experience in contested races.