Having purged their faculties more than a decade ago of those suspected of conservative leanings, the campus progressives are now going after their own.

Haverford College recently disinvited Robert J. Birgeneau, the former Chancellor at UC Berkeley. A man with impeccable progressive credentials, Birgeneau's offense was to allow the Berkeley police to use force against "Occupy" protestors in Sproul Plaza in 2011 -- negating a career-long commitment to progressive causes including advocating for undocumented immigrants and promoting the LGBT community on campus.

Surprised by the students’ animosity toward Birgeneau, Haverford’s president, Daniel Weiss complained that his students were acting more like a jurors “issuing a verdict” than a campus community extending an invitation for “shared learning.”

Weiss should have noticed that “shared learning” disappeared decades ago from colleges like Haverford.

He may have missed the memos on the well-qualified conservatives who were passed over for faculty jobs at his school.

Having served on administrative and faculty search committees for fifteen years as chair of a West Coast sociology department, I have seen those memos. The discrimination is real — and it occurred on campuses across the country.

The result is that there are few faculty conservatives, and even fewer conservatives in leadership positions. A few years ago, conservatives were encouraged to learn that one of two finalists for the presidency of Seton Hall was Monsignor Stuart Swetland, a faithful priest, and a Rhodes scholar who graduated first in his class from the U.S. Naval Academy.

Swetland was uniquely qualified for the job as he has served as vice-president for Catholic identity and mission at Mount St. Mary’s in Maryland, and has been directly involved in revitalizing the Catholic identity on Catholic campuses like Seton Hall.

But, signs of doom for Swetland were clear when the other candidate for the presidency withdrew his name from consideration, and a headline in the New Jersey Star-Ledger warned: "Anticipated Seton Hall President Thought to be a Conservative Choice."

The search was suspended and although Seton Hall officials deny it, strong resistance from the faculty to hiring a faithful Catholic priest like Monsignor Swetland to lead the school had an impact on the failed search.

In their witch hunt to destroy the careers and the lives of the few tenured conservatives that were left teaching on their campuses, the progressive faculty began to run out of witches.

“Conservative” had to be defined down to include a pro-choice progressive who supports same-sex marriage but had concerns about allowing “occupying” students to destroy university property.

"Conservative" is now defined as a professor who was once viewed as progressive because of her success in writing grants that brought social services to the poor in the neighborhood adjacent to the university, but when she began to have concerns about allowing students at her Catholic college function as clinic escorts at abortion clinics for internship credit, she became the enemy on her campus.

“Conservative” on today's campuses can now be defined as anyone who supports capitalism. At Smith College, students and faculty protested the choice of Christine Lagarde as commencement speaker because the powerful leader of the International Monetary Fund was connected to an “imperialistic” economic system.

We are all conservatives now. But, in some ways, this broadened definition of “conservative” may actually be a hopeful sign for the future.

Like the Salem witchcraft trials of the 1600s in Massachusetts, the desperate hunt for more witches spread throughout New England and resulted in the witch hunters beginning to turn on each other.

Respected clergymen and community leaders who had become swept up in hunting for witches began to be defined as witches themselves.

The hysteria finally ended when the wife of the Massachusetts governor was accused of practicing witchcraft.

In 2012, Connecticut Governor Dannel Malloy issued a proclamation condemning the witchcraft prosecutions — clearing the “witches” names, and denouncing the executions of innocent men and women.

While we cannot expect progressive faculty and administrators to denounce their role in the shunning and the marginalization of their conservative colleagues, the discrimination will end as parents and students realize that there are alternatives.

The growing availability of apolitical online courses and the flourishing of a few dozen college and university campuses that have resisted the call to remove ideologically diverse voices now offer students a real choice.

Anne Hendershott is Professor of Sociology and Director of the Veritas Center at Franciscan University of Steubenville, Ohio. She is the co-author of Renewal (Encounter Books).