A Muslim human rights group has issued a strong response to the allegations from House Republican members that longtime Hillary Clinton aide Huma Abedin's family, as well as other prominent Muslim-Americans working within the U.S. government, have ties to Egypt's Muslim Brotherhood.

Corey Saylor, a spokesperson for the Council on American-Islamic Relations, also known as CAIR, calls questioning the loyalty of "patriotic American Muslims" based on what he says are old anti-Muslim conspiracy theories "beyond the pale."

Five GOP members of Congress, including former presidential candidate Michelle Bachman, sent letters to the Inspector General offices for the State Department, as well as the Departments of Homeland Security, Justice, Defense and the Office of the Director of National Intelligence, questioning whether Abedin and other prominent Muslims are part of a plot by Islamic extremists to infiltrate the U.S. government.

"America wants a serious national security conversation," says Saylor. "Michelle Bachmann is giving us a six degrees of separation drinking game ."

CAIR, a Washington-based Islamic advocacy group founded in 1994, is not alone in its condemnation. Today veteran Republican Senator John McCain gave a spirited defense of Abedin, calling the allegations against her "ugly" and "sinister." He chastised his GOP colleagues in the House saying that no one, "not least a member of Congress," should launch such a "degrading attack against fellow Americans on the basis of nothing more than fear of who they are and ignorance of that they stand for."

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State Department deputy spokesperson Patrick Ventrell also shot down the accusations, calling them "preposterous."

Saylor says that Abedin and the other Muslim officials listed in the House letter are American citizens who are "asking what they can do for their nation," and now Bachmann "seems to be punishing them for the sin of offering that service during a Democratic administration," he says.

In addition to Abedin, the letters also cite Mohamed Elibiary, an advisor to the Department of Homeland Security named in the letter, as also having possible ties to extremists. Last year Elibiary was given an award by the Society of Former Special Agents for his counter-terrorism work with the FBI.

"Now his contributions have been rewarded by Bachmann questioning his patriotism," says Saylor.

Minnesota Representative Keith Ellison, the only Muslim member of Congress, has sent letters to Bachmann demanding she and her GOP colleagues produce evidence backing up their claims. Ellison told CNN's Anderson Cooper that the allegations are "the worst of guilt by association," said Ellison. "It is a stark affront to American values."

Bachmann has issued a statement saying that Ellison has "distorted" the letters by taking certain comments out of context. "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," said Bachmann.

But those who have spoken out, including McCain, Ellison and CAIR, reiterate that Bachmann and her House GOP colleague's questions aren't based on credible evidence. Saylor says it has more in common with the 1950's political witch hunt spearheaded by former senator Joe McCarthy to take down political opponents by claiming they were communists. That period is generally seen as one of the darkest in American political history.

"You can't help drawing parallels between this and McCarthyism," says Saylor. "Half truths? Guilt by association? Overblown accusations? Sounds like Joe McCarthy to me."

ABC's Sunlen Miller and John Parkinson contributed to this report