A now-former Georgetown Law lecturer who was placed on leave following a critique of President Biden's race-based rubric for nominating Supreme Court justices told Fox News Tuesday why he has resigned.

Ilya Shapiro, who was most recently cleared in the investigation that followed his suspension, said he could not remain at Georgetown. He said he could not say at an institution where another instance of someone complaining they are "offended" during future lectures could lead to a repeat of the controversy that has embroiled him.

"[N]ationwide and in Georgetown specifically, there are a lot of cowardly administrators who refuse to stand up to the activist, radical woke mob who insists that there is no deviation from a progressive orthodoxy," he said.

"Contrary to the ‘diversity equity inclusion’ officers that have proliferated throughout the land, they are discouraging intellectual diversity, preventing equal opportunity, and excluding any voices that would dissent from the prevailing view."

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Ilya Shapiro at a lecture

Ilya Shapiro (YouTube)

Earlier this year, Shapiro drew Georgetown's ire after he tweeted about the fact Biden would be choosing a Supreme Court nominee – in this case Ketanji Brown Jackson – based on the immutable characteristics of race and gender, versus the customary analysis of a particular nominee's merit and qualifications.

Biden had promised that he would nominate a Black woman to the Supreme Court. (Ironically, Jackson later caused controversy during her confirmation hearing when she declined to state the definition of a "woman" under questioning by Sen. Marsha Blackburn, R-Tenn.)

Shapiro had lamented Biden's pledge effectively excluded District of Columbia Circuit Court Chief Judge Sri Srinivasan, who is Indian-American.

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Georgetown University campus

Georgetown University in D.C. ((AP/Jacquelyn Martin))

Shapiro said Srinivasan "doesn't fit the intersectional hierarchy so we'll get a lesser Black woman," going on to say the nominee would forever have an "asterisk" next to her name – and suggested Biden expressed open sexism and racism.

Shapiro soon took down the tweets, which he called "inartful" and said undermined his message.

"[I]t's ironic… that I was put under investigation for criticizing Joe Biden for applying a racial and gender-based test for his Supreme Court nominees," Shapiro told Fox News' Tucker Carlson.

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Shapiro added Georgetown Law "insinuated" that he or other faculty who wrote something deemed offensive would be creating a hostile educational environment.

"I could not work under that arrangement," he said.

Shapiro said he has accepted a new position at the New York-based Manhattan Institute as director of Constitutional Studies.

Fox News' Tyler Olson contributed to this report.