Representatives Steve King of Iowa and Michele Bachmann of Minnesota are among the lawmakers siding with anti-gay groups.
The Republicans have joined an online petition protesting the claims of the Southern Poverty Law Center (SPLC).
The SPLC recently added the Family Research Council (FRC), the American Family Association (AFA) and the National Organization for Marriage (NOM) to the same list of hate groups as the Ku Klux Klan, the Nation of Islam and the Aryan Nations for their opposition to gay rights.
“We, the undersigned, stand in solidarity with Family Research Council, American Family Association, Concerned Women of America, National Organization for Marriage, Liberty Counsel and other pro-family organizations that are working to protect and promote natural marriage and family,” the open letter, sponsored by the FRC, reads. “We support the vigorous but responsible exercise of the First Amendment rights of free speech and religious liberty that are the birthright of all Americans.”
The SPLC has “targeted FRC and other organizations that uphold Judeo-Christian moral views, including marriage as the union of a man a woman.”
Booth Gunter, a spokesman for the SPLC, on Friday rejected the allegations.
“The bottom line is it's simply not true that we attacked them because of their Judeo-Christian beliefs or their opposition to gay marriage,” Gunter told Fox News. “It's because of their continued propagation of falsehoods about gay men and lesbians that have the effect of demonizing them.”
Also signing onto the letter are Majority Leader-elect Eric Cantor, House Speaker-elect John Boehner, presidential hopefuls Tim Pawlenty, Rick Santorum and Mike Huckabee, Representatives Jim Jordan of Ohio and Louie Gohmert of Texas, and South Carolina Senator Jim DeMint.