Most of the purported news we get about our nation’s higher education is about the ponderous tuition debt that accompanies many college graduates. But Americans are entitled to know how many of our colleges and university administrators are censoring and punishing the free expressions of students and, yes, professors — whether they are liberals, conservatives or independents.

When I was going to college in the 1940s and 1950s at Northeastern University and Harvard, students vividly debated one another and their professors on controversial issues. So I would have never guessed that an extensive study pertaining to free speech on college campuses, titled “Engaging Diverse Viewpoints” and conducted by the respected Association of American Colleges and Universities (AAC&U), would be necessary in this land of the free and home of the brave.

In the 2010 study, the sampled 24,000 college students were asked whether they thought it was “safe to hold unpopular views on campus.”

Keep in mind they weren’t asked about expressing unpopular views — just holding them. Here are the results:

“Among the college seniors in the survey sample, only 30.3 percent answered that they strongly agreed that ‘it is safe to hold unpopular views on campus.’”

This information is from “Unlearning Liberty” (Encounter Books), a book coming out next month by Greg Lukianoff, president of the Foundation for Individual Rights in Education (FIRE), the only full-time organization exposing and diligently combatting the transformation of future leading Americans into passive pawns of authoritarian governments.

Lukianoff continues with the results of AAC&U’s fearful survey:

“Even more alarmingly, the study showed that students’ sense of the safety of expressing unpopular views steadily declines from freshman year (starting at 40.3 percent) to senior year… But the students were downright optimistic compared to the 9,000 ‘campus professionals’ surveyed, including faculty, student affairs personnel, and academic administrators. Only 18.8 percent strongly agreed it was safe to have unpopular views on campus.

“Faculty members, who are often the longest-serving members of the college community and presumably know it best,” adds Lukianoff, “scored the lowest of any group — a miserable 16.7 percent!”

Lukianoff speaks from extensive and intensive experience, as he writes in “Unlearning Liberty”: “This book grew out of my experience reviewing thousands of instances of campus censorship and defending faculty and students at hundreds of colleges across the country over the last eleven years.”

In cases involving public universities and colleges, they are required by the First Amendment to protect freedom of speech and the academic freedom of students and professors. But how come some of FIRE’s insistent interventions have been at private universities, where blocking free speech is not a matter of state action?

In a recent column for the website RealClear Religion, Lukianoff writes that FIRE gets involved because “most private colleges — like Yale and Harvard — promise free speech and other basic rights in glowing language” (“Not at Liberty to Discuss,” www​.real​clear​reli​gion​.org, Sept. 14).

The promise made to students and faculty is, Lukianoff explains, “binding legal precedent in most states, where courts have held that colleges may be required to honor the contractual promises they make.”

Students accepted at private colleges and universities — and parents helping to pay their tuition — should be mindful of this contractual obligation by those private universities.

If my children, now mostly in their 50s, were young enough to be applying to colleges, I’d be much troubled by what Lukianoff recently told me:

“It’s easy for students to get caught up in the frenzy of trying to get into the best-ranked schools. But if the college you attend doesn’t respect free speech, your education will suffer, regardless of how high the college is ranked.”

And your country will suffer, too.

All Americans, no matter their political affiliation, should also recognize that this sentiment is further evidenced by a 2004 John S. and James L. Knight Foundation survey of 100,000 high school students, which found: “Nearly three-fourths (73 percent) either say they don’t know how they feel about the First Amendment, or they take it for granted.”

Obviously, then, colleges and universities that continue to shut down diverse viewpoints further guarantee that future generations of Americans will not know whom the Declaration of Independence refers to.

I write this with much foreboding as to how much of our constitutional individual liberties will remain active — whomever ends up in the White House.

After all, with the fortunes being spent on what the presidential candidates have warned would be the most important election in our history, I have not heard a word from them about how our colleges and universities subvert the core of our self-governing republic: the citizens’ freedom of expression and conscience.

How about Greg Lukianoff for president next time around?

Meanwhile, let’s continue to strengthen and deepen the growing number of teachers who are arousing their students in lively civics classes, engaging them in debates as they learn how to become authentically involved citizens — before they even arrive on college campuses.

I’ve witnessed kids get high on the Bill of Rights. Once they absorb a thrilling sense of who they are as Americans, they never get enough.