Speaking to conservative radio host Glenn Beck on Thursday, Bachmann declined to respond to her Republican critics, but attempted to smear Ellison by associating him with Islamic radicals.

"So when you wrote this letter, then Keith Ellison comes out," Beck told Bachmann. "Keith Ellison is -- he has a record of being the Mafia hitman."

"Well, [Ellison] has a long record of being associated with CAIR and with the Muslim Brotherhood," Bachmann agreed. "[S]o he came out and essentially wanted to shut down the inspectors general from even looking into any of the questions that we were asking. So he wanted to shut it down. In response I wrote another letter back to Keith Ellison, a 16-page letter which I would encourage all of your listeners to go and read this letter. It’s what I call a bulletproof letter."

"And so then now what’s happened is the attack machine has been turned on myself and the other members of congress who have been asking the questions, that somehow we’re the Muslim haters, we’re the witch-hunters, we’re the new Joe McCarthyites because we’re asking these questions," she insisted.

Later on Thursday, Ellison told CNN's Anderson Cooper that Bachmann's charges were "ridiculous."

"That's not true," the Minnesota congressman explained. "I don't have any Muslim Brotherhood connections that she's talking about."

"I'm absolutely not trying to shut down their investigation. What I'm trying to do is raise a concern about unfounded allegations of disloyalty, specifically with regard to Huma Abedin and a few other people who she mentioned."

Ellison continued: "It's about marginalizing and alienating a group of Americans who she does not view as all-American enough."