Sen. John McCain ripped into a posse of GOP lawmakers led by Rep. Michele Bachmann (Minn.) on Wednesday for targeting Huma Abedin — a top aide to Secretary of State Hillary Rodham Clinton, the wife of former Rep. Anthony Weiner (D-N.Y.) and a Muslim — in their quest to identify allies of the Muslim Brotherhood within the Obama administration.

McCain said the attacks on Abedin in a June 13 letter from five House Republicans, and a related report from the Center for Security Policy, run counter to the truth and to the values of the United States.

“The letter and the report offer not one instance of an action, a decision or a public position that Huma has taken while at the State Department or as a member of then-Sen. Clinton’s staff that would lend credence to the charge that she is promoting anti-American activities within our government,” the Arizona Republican said on the Senate floor.

“These attacks have no logic, no basis and no merit, and they need to stop. They need to stop now,” McCain said. “Ultimately what is at stake in this matter is larger even than the reputation of one person. This is about who we are as a nation and who we aspire to be. … When anyone, not least a Member of Congress, launches specious and degrading attacks against fellow Americans on the basis of more than fear of who they are and ignorance of what they stand for, it defames the spirit of our nation and we all grow poorer because of it.”

Bachmann responded with a statement saying that the June 13 letter and a follow-up letter she wrote last week to Rep. Keith Ellison (D-Minn.), who is also a Muslim, had been “distorted.”

Her statement did not directly name McCain.

“I encourage everyone, including media outlets, to read them in their entirety,” she said. “The intention of the letters was to outline the serious national security concerns I had and ask for answers to questions regarding the Muslim Brotherhood and other radical group’s access to top Obama administration officials. … I will not be silent as this administration appeases our enemies instead of telling the truth about the threats our country faces.”

Her letter to Ellison on Friday specifically questions how Abedin obtained a security clearance given what Bachmann called her family’s ties to foreign extremist organizations.

In addition to Bachmann, Reps. Trent Franks (Ariz.), Louie Gohmert (Texas), Lynn Westmoreland (Ga.) and Tom Rooney (Fla.) signed the June 13 letter.

Copies of the House Members’ letter were sent to the inspectors general of Office of the Director of National Intelligence, the Defense Department, the Department of Homeland Security, the Justice Department and the State Department.

In their State Department letter, the five single out Abedin as someone who, according to the Center for Security Policy report, “has three family members — her late father, her mother and her brother — connected to Muslim Brotherhood operatives and/or organizations.” They also cite several other administration employees at other departments who they say may be connected.

The lawmakers also specifically accuse Clinton and the State Department of having “taken actions recently that have been enormously favorable to the Muslim Brotherhood and its interests.”

The Muslim Brotherhood is an Islamist political party founded in Egypt with affiliates throughout the Arab world. While the group won recent Egyptian elections, they have been rebuffed by Libyan voters. During last year’s “Arab spring,” speculation in the U.S. centered on the potential dangers of the brotherhood taking hold, while others wondered whether they might be a moderating force to more extreme elements.

But conspiracy theories abound about the brotherhood’s influence on U.S. politicians in both parties. Among the Center for Security Policy “Muslim Brotherhood in America” report’s key findings was an unsubstantiated allegation that “the Muslim Brotherhood was helped in its efforts to achieve information dominance over the George W. Bush administration, thanks to collaboration between a top Muslim Brotherhood operative, Abdurahman Alamoudi, and anti-tax activist Grover Norquist. In addition to al Qaeda financier Alamoudi, Norquist helped mainstream in the Bush campaign and/or administration five other Muslims with extensive ties to the Muslim Brotherhood.”

Norquist and the center’s leader, Frank Gaffney, have sparred over the issue for years. In a 2003 open letter to Gaffney, Norquist accused him of racial prejudice and religious bigotry.

Emily Pierce contributed to this report.