Jason Riley must be suffering from whiplash. This spring, the Wall Street Journal columnist and scholar with the prestigious Manhattan Institute was invited, then disinvited, and now finally re-invited to give a lecture at Virginia Tech’s Pamplin College of Business as part of its Distinguished Lecture series.

Why all the back and forth?  The controversy stems from the fact that Riley is a conservative in an era when conservative viewpoints are unwelcome on many college campuses. Riley thus joins a long list of right-leaning analysts and policymakers – including George Will, Greta Van Susteren, Ann Coulter, and Scott Brown  — whom activists have sought (with mixed results) to “disinvite” from campus speaking engagements around the country.

But Riley’s politics are only partially to blame for his “disinvitation.” If politics alone were the issue, Virginia Tech would not have hosted a lecture earlier this year by conservative scholar Charles Murray.

To be sure, student protests of Murray’s lecture made Virginia Tech administrators skittish about bringing Riley to campus — one conservative is more than enough! But Riley’s main offense is not that he is a conservative, it is that he is a black conservative who not only expresses conservative viewpoints on economics and foreign affairs, but who dares to challenge the liberal orthodoxy on race.

Riley is the author of “Please Stop Helping Us: How Liberals Make It Harder for Blacks to Succeed,” which argues that well-intentioned government efforts to help blacks have actually hurt many of their intended beneficiaries. Moreover, Riley’s columns often argue that conservative policy prescriptions for education, criminal justice, and welfare reform better serve the black community than liberal alternatives.  It is these views that raised eyebrows at Virginia Tech.

As National Association of Scholars president Peter Wood reported last week in the National Review, “[t]he head of the finance department had not initially objected to Riley … but later, when he realized that Riley had ‘written about race issues’ in the Wall Street Journal, he decided Riley would have to go.”

Put simply, Riley had to go because his writings contradict the narrative that racism is endemic to America, and they challenge the assumption of many on the Left that our benevolent leaders must stamp out racism with massive government programs and forced demographic proportionality in all walks of life.

Riley is not the only black campus speaker whom activists have attempted to banish for racial apostasy. In 2013, the Rev. Kevin Johnson of Bright Hope Baptist Church in Philadelphia was scheduled to deliver the graduation address at Morehouse College, his alma mater, but was “disinvited” after writing an editorial critical of President Obama.

In 2014, Brandeis University shamefully revoked an invitation to Somali-born Ayaan Hirsi Ali because of her vocal critique of her own Islamic culture. One month later, activists pressured former Secretary of State Condoleezza Rice to withdraw from the Rutgers commencement. Rice’s opponents claimed they objected to her role in the Iraq war. But, make no mistake about it, Rice’s refusal to embrace victim politics had long made her a pariah to the Left, regardless of her role in crafting President Bush’s foreign policy.

Unfortunately, this war on right-leaning minorities is not a recent phenomenon, nor is it limited to the battlefield of the college campus. To the contrary, President George H.W. Bush’s 1991 nomination of Clarence Thomas to the United States Supreme Court reminds us that combatants have been fighting this battle for a very long time.

Liberals would, of course, have, opposed any conservative nominee to replace liberal Justice Thurgood Marshall. But their vitriolic campaign against Thomas was fueled by the fact that Thomas was an African American who had questioned the fairness of racial preferences and the effectiveness of the welfare state; a man who had risen from poverty in Pinpoint, Georgia to become a federal judge on one of the most prestigious courts in the land; a man whose life story and worldview contradicted the Left’s racial agenda.

Thomas was ultimately confirmed to the High Court. But, since then, those who disagree with the Justice’s politics have spared no effort to delegitimize him by portraying him as a lackey of the late Justice Antonin Scalia. The meme of Justice Thomas as incapable of forming his own opinions, and silent on the bench because of a purported lack of intelligence could not be further from the truth. Thomas is, in fact, one of the Court’s most prolific writers, and anyone who has read a Thomas opinion knows that he is an independent, principled, thoughtful jurist. Even before Scalia’s untimely death, Thomas was, arguably, the court’s conservative intellectual leader.Yet, tellingly, many liberals who have praised Scalia’s intelligence, while disagreeing vehemently with his jurisprudence, refuse to offer the same respect to Thomas.  Why?  If they did, their words might give credence to the notion that conservatism is not just for white people.

A decade after the Left lost the Thomas confirmation fight, activists launched a scorched earth battle to prevent the confirmation of Miguel Estrada, another conservative minority, to the U.S. Court of Appeals for the D.C. Circuit. Notably, a leaked memo to a Democratic member of the Senate Judiciary Committee described Estrada, a Honduran immigrant, as “especially dangerous because … he is Latino.”

Estrada, who was indisputably well-qualified for the post and had the support of a majority of senators, should have been easily confirmed. But Senate Democrats were so threatened by the thought of this conservative Hispanic that, for the first time in history, they filibustered a nomination to the court of appeals. After six months, Estrada withdrew his name from consideration.

It is, indeed, ironic that the loudest proponents of ethnic and racial diversity often mistreat conservative blacks and Hispanics. But it is not surprising, given the existential threat that right-leaning minorities pose to the liberal agenda.

Those who are genuinely committed to diversity, however, understand that minority communities are not politically monolithic. They welcome ideological diversity, not just diversity based on immutable characteristics, and they understand that perspectives such as Jason Riley’s do much to enrich our political and civic discourse. Sadly, diversity’s false prophets can’t seem to accept this.