Rep. Michele Bachmann (R-MI) said she stood by five letters alleging that Muslim extremists had infiltrated the U.S. government in a debate Sunday against Democratic challenger Jim Graves.

"I certainly do stand by those letters, because what we know is that terrorism continues to remain a very real threat in the United States," Bachmann said. "I serve on the [House] Intelligence Committee. We deal with deal with the classified secrets of the nation."

The five letters, sent by Bachmann and four other GOP lawmakers in July to inspectors general in the Defense, Homeland Security, Justice and State departments, called on officials to look into "potential Muslim Brotherhood infiltration" by Huma Abedin, a former aide to Secretary of State Hillary Rodham Clinton, and prompted fellow Republican Rep. John McCain (R-AZ) to criticize them on the Senate floor, calling them "specious and degrading attacks."

Bachmann subsequently ran away from a CNN reporter when asked to respond to McCain's remarks, an incident she didn't mention to moderator Tom Hauser, insisting that "a number of people" came to her in support of the letters.

She also repeated her accusation that the Brotherhood was behind the Sept. 11 attack on a U.S. consulate in Benghazi, Libya, which "proved" that the country was under attack both at home and abroad.

When Hauser pointed out that the Brotherhood, the party of current President Mohamed Morsi, has not been connected to the attack that killed Ambassador Chris Stevens and three other Americans, Bachmann called it "a violent organization."

For his part, Graves said he stood with McCain and other Republicans who called Bachmann out on her tactics like House Speaker Rep. John Boehner (R-OH) and Rep. Lindsey Graham (R-SC).

"We don't need to polarizing, we don't need to be throwing mud, especially when it's uncalled for," Graves said. "Here's the thing: there's nothing more important in this country, nothing more important than the federal government is to protect these people and I stand behind that 100 percent. But we don't need to polarize, we don't need to antagonize, we don't need to be throwing mud, especially when it's not even called for."

Bachmann also denied even making accusations at all, saying the letters were just "asking questions."

"It's certainly within reason to think these violent organizations who declare, almost on a weekly basis, they want the destruction of Israel and they want the destruction of the United States," she said. "When madmen speak, listen and pay attention."

Watch Bachmann and Graves discuss her allegations regarding the Middle East, posted on YouTube Monday by user Faiz Shakir, below.

[h/t Salon]