Media Matters For America founder David Brock admitted Monday that his nonprofit, tax-exempt organization specifically defends Hillary Clinton, a political candidate for office, from Republican criticism.

Brock’s stunning admission calls into question the nonprofit status of his left-wing media monitoring organization.

Brock made the admission in an op-ed defending his group’s association with Sidney Blumenthal, Hillary Clinton’s political adviser and informal Libya consultant.

Blumenthal fed Clinton information from Media Matters while advising the former secretary of state in the aftermath of the Benghazi terrorist attack. Blumenthal was serving as a paid Media Matters consultant at the time.

Blumenthal testified in a closed-door session last week with Rep. Trey Gowdy’s House Select Committee on Benghazi.

“By refusing to release the transcript, the Republicans want to hide the true nature of the Blumenthal deposition: Their partisan attempt to both chill Blumenthal’s right to freely express his own political views and more broadly to intimidate our organizations — organizations that have led the way in exposing the fraudulence of the Benghazi investigation itself. (Not to mention our role in specifically defending Hillary Clinton from the Republicans’ unfair attacks on the subject),” Brock wrote.

Media Matters is a 501(c)(3) nonprofit organization.

“Under the Internal Revenue Code, all section 501(c)(3) organizations are absolutely prohibited from directly or indirectly participating in, or intervening in, any political campaign on behalf of (or in opposition to) any candidate for elective public office,” according to IRS rules.

“Violating this prohibition may result in denial or revocation of tax-exempt status and the imposition of certain excise taxes,” according to the IRS.

Blumenthal and Brock have a longstanding relationship dating back to the 1990’s. Blumenthal has been credited with helping bring Brock, formerly a conservative journalist, into the Clinton-world political establishment.

Brock did not return a request for comment.

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