The denial of a speaking engagement to conservative commentator Ann Coulter at the University of California at Berkeley is getting a lot of coverage right now, but it’s nothing new. For many decades, there has been a stunning — and manifestly appalling — general prejudice against conservatives in higher education, evidenced by curtailments on their academic freedom and freedom of speech.

It is difficult for conservatives to get hired, and once hired, it is difficult for them to get promotion and tenure — particularly in the humanities and social sciences, wherein liberal orthodoxy rules.

This has resulted in fewer conservatives finding their way into academe as a profession, which liberals disingenuously claim is the result of universities having limited economic attraction for those on the right, not as a result of unfair practices.

I have been a high-profile conservative at Towson University for decades, one of the less discriminatory public universities. I have also been elected and re-elected to our University Senate for decades, a tribute to a faculty motivated by fairness. Still, Towson is, like almost all public universities, heavily weighted toward the left.

Even at Towson I have encountered outrageous attacks on my academic freedom. A staff member heard me criticize The Sun a decade ago and said her department would not help me if she ever heard such criticism again. When I complained to higher-ups, they took her side.

But the discrimination against conservatives in higher education is a mile wide and a mile deep.

Several years ago in a survey by the University of California at Los Angeles Higher Education Research Institute (HERI), it was found that at New England universities progressive professors outnumber conservative professors by 28 to 1. Yes, that’s 28 to 1.

Various other studies have found large humanities departments in major universities without a single conservative.

A 2014 HERI report found that 60 percent of professors nationwide identified as left leaning and that they outnumbered right-leaning educators by 5 to 1.

The liberal-conservative professoriate divide is a self-perpetuating phenomenon. Many liberals insist that their curriculum should also be left-leaning, along with their campus administrators, and they hire only those professors and administrators who will support that political position.

The students who have predominantly liberal professors end up supporting the orthodoxy of their professors, and teachers who lack integrity ensure that academic rewards of good grades, recommendation letters and general support go only to those students who follow their belief system, especially in non-business and non-scientific areas.

Thus, student bodies become low-intensity progressive, and they change only when they have experienced the hard realities of the workaday world and marriage and parenting. Consequences of people’s positions often produce nuanced ideological change.

Will the academy ever work to produce ideological diversity? Well, President Kim Schatzel of Towson argued for just such diversity in her semi-annual address to the faculty. I haven’t heard of any other college or university presidents doing so.

We shall see.

Richard Vatz (rvatz@towson.edu) teaches at Towson University and is author of “The Only Authentic Book of Persuasion: the Agenda-Spin Model” and co-editor of the forthcoming “Thomas S. Szasz: the Man and His Ideas.”