MADISON, Wis. (CBS 58) -- A U.S. Senator is calling for federal investigators to review the state criminal case against the lawyer who represented President Donald Trump in his effort to throw out hundreds of thousands of Wisconsin votes in 2020.

GOP Sen. Ron Johnson wrote a letter to Attorney General Pam Bondi Thursday asking for the U.S. Department of Justice to get involved in the case against Jim Troupis, who is one of three men charged in Wisconsin for their alleged role in trying to pass along a fake slate of GOP presidential electors after the 2020 election.

Johnson highlighted claims from Troupis' legal team that the Dane County judge presiding over the case, John Hyland, did not actually write a previous decision rejecting Troupis' motion to dismiss the case.

Instead, Troupis claims the decision was written by former Dane County judge Frank Remington. Troupis' lawyer, Joseph Bugni, maintained he's familiar with Hyland's writing from previous cases and claims Hyland did not write the August decision.

Hyland has since said he did write the decision. Troupis is now asking for Hyland and every other Dane County judge to be taken off the case.

Johnson now wants federal investigators to take a look at whether Troupis can be guaranteed a fair trial.

"It is difficult to understand how Judge Hyland can make an impartial decision," Johnson wrote. "I respectfully request that the
Department of Justice review Mr. Troupis’ case to determine whether any wrongdoing has occurred."

Troupis, Kenneth Chesebro, a Wisconsin native who helped coordinate the fake elector plot across multiple states, and former Trump aide Mike Roman were charged in Wisconsin with forgery.

The defendants have said they were only collecting the list of electors in case courts overturned former President Joe Biden's victory in Wisconsin.

However, investigators have connected Johnson, himself, to efforts to bring slates of fake GOP electors to then-Vice President Mike Pence on January 6, 2021.

Text messages showed Johnson connecting Troupis with his chief of staff on the morning of January 6. 

Johnson has repeatedly denied any wrongdoing, telling CBS 58 in December 2023, "I didn't connect Jim. Jim Troupis called me up, asked if I could help deliver something to the vice president. That's all I knew. I had no idea."

A spokesperson for Troupis said he was unavailable for an interview Friday, Dec. 12, but passed along a statement.

"I am pleased that Senator Johnson recognizes the gravity of the misconduct by the Dane County Court," Troupis wrote. "It is long past time for the United States Department Justice to enter the proceedings and bring an end to Wisconsin Attorney General Josh Kaul’s obvious political witch hunt".

The Wisconsin Department of Justice did not immediately respond to a request for comment Friday.