GOP presidential candidate Dr. Ben Carson is going after CAIR – an organization linked to terrorism – again, sending out an email to supporters to call for an investigation into this “non profit organization.”

CAIR, a “Muslim advocacy” group, went after Carson, calling for him to withdraw from the GOP presidential race because he said he wouldn’t support a Muslim who wouldn’t abide by the U.S. Constitution to be President of the United States.

“Over the past week, I’ve come under attack from the media, the Left and even some of my Republican peers for saying that many parts of Shariah law are incompatible with the U.S. Constitution, and that I couldn’t advocate a Muslim candidate for president unless these tenets were fully renounced,” Carson wrote to his supporters.

Breitbart News’ Jordan Schachtel revealed that CAIR, described as a “Muslim advocacy group” and a “civil rights organization” by the left and the mainstream media, is actually tied to Hamas, a designated Palestinian terrorist group.

CAIR’s founder and current leader, Nihad Awad, has proven ties to Hamas, a U.S.-designated Palestinian terrorist group. FBI wiretaps found that Awad asked early CAIR employees to use coded-language when discussing their support for Hamas, due to its terror designation.

CAIR also has significant ties, if not membership, with the global Muslim Brotherhood, as the founders of CAIR were all members of Muslim Brotherhood-launched outfits.

Carson is calling on his supporters in a Saturday morning email to push back against CAIR for the organization’s attempt to silence Carson, circulating a petition that would call for the IRS to revoke CAIR’s tax exempt status.

“Here’s the catch — CAIR is a tax-exempt nonprofit, and IRS rules explicitly prohibit such groups from intervening in political campaigns on behalf of — or in opposition to — a candidate,” Carson stated.

This is not the first time that CAIR has disrespected U.S. laws or America. It previously lost its tax-exempt status by failing to file federal taxes three years in a row. It’s also been named by federal prosecutors as an unindicted co-conspirator in a criminal conspiracy to funnel money to Hamas, a terrorist organization.

Under the Obama Administration, the IRS has systematically targeted conservative nonprofit groups for politically motivated audits and harassment. The agency should now do its job properly and punish the real violators of American laws and regulations.

Despite CAIR’s attack on Carson, his campaign raised $700,000 in the 36-hours following the backlash from his statement regarding a hypothetical Muslim president.

Breitbart News attended a press conference held by CAIR on the issue, but was ejected once a question about its terrorist-tied foundation was asked.