What do Harvard, Yale, the University of Pennsylvania, Dartmouth, Vassar, Tufts, MIT, the University of Virginia and Colby College have in common?

Elite college commencements again this year will be an  intellectual cordon sanitaire. Who will be exposed to unorthodox or unconventional thoughts?

Simple.  They are all members of the Big Sixty, schools ranked by US News as the top thirty universities and top thirty colleges in the country. This spring they will all be holding commencement ceremonies for their graduates, young men and women bred and educated to take their places in the American leadership class.   

Elite college commencements again this year will be an  intellectual cordon sanitaire. Who will be exposed to unorthodox or unconventional thoughts?

At these ceremonies, students will be provided with advice from suitable (i.e. Democratic) orators running the ideological gamut from Arianna Huffington to Robert Redford to Joe Biden to Madeleine Albright, Governor Terry McAuliffe to Ambassador Samantha Power (a double dip at Barnard and Penn).  And so on.

Among the Big Sixty schools that have already announced their commencement speakers, there are twenty-two political figures or public intellectuals with a clear progressive/liberal identity. A twenty-third, former Secretary of State Colin Powell, nominally belongs to the GOP but he endorsed President Obama in 2008 and 2012. The only authentic Republican on the list is ex-Secretary of State Condoleezza Rice.  So make it 23-1.

Last year, Secretary Rice was forced to withdraw as the Rutgers commencement speaker after protests by Muslim students.  Human Rights activist Ayaan Hirsi Ali was disinvited by Brandeis for criticizing Islamic misogyny and homophobia. Smith College and Haverford also disinvited speakers deemed guilty of politically incorrect thoughts.

In a commencement speech at Harvard in 2014, former New York mayor Michael Bloomberg denounced this epidemic of cancellations as a manifestation of left-wing academic McCarthyism. He called on the country’s top schools to demonstrate their commitment to freedom of thought by inviting distinguished conservatives to address their graduates.

These schools have done no such thing this year.  Instead, they have put safety first by not even trying to invite anyone who is remotely objectionable to their bien-pensant faculty and a handful of obnoxious student “activists.”

Democratic office holders and appointees vetted by the Obama administration are fine (as long as they don't oppose President Obama on any significant issue).

So are the heads of liberal institutions (Ford Foundation, Aspen Institute), progressive celebrities (Ken Burns, Shonda Rhimes), high-tech entrepreneurs (excepting those who contribute to the GOP) and apolitical humanitarians (so long as they are not conservative Christians). 

As a result, elite college commencements again this year will be an  intellectual cordon sanitaire. Who will be exposed to unorthodox or unconventional thoughts? Students at Evangelical universities (Jeb Bush is the speaker at Liberty University and his brother George will be at Southern Methodist University), graduates of a decreasing number of right-leaning Catholic schools and seniors at some “second-tier” public and private institutions, mostly in Red States.  Most Americans won't hear these speeches, which is a shame. Many are full of hard won wisdom by brilliant contrarians.

Of course, many of the speakers at the Big Sixty (and their imitators) are distinguished and worth listening to as well.  And it is unlikely that even students exposed to the thoughts of Arianna Huffington or Joe Biden will suffer any lasting damage.

Many students at elite universities leave college under the impression that their values are universally shared by anyone worth knowing.  Often they depart without  understanding that there are bright, virtuous and committed conservatives. This illusion puts them at a disadvantage when they find themselves competing with contemporaries who do not share their certainties or bow to their presumed superiority.

One last lecture from a Democratic politician or a Hollywood environmentalist is not going to make a liberal graduate any more savvy about life after college.  But exposing him or her to a new idea--that there is a universe of brilliant and determined conservatives beyond the walls of the campus--would be a valuable piece of information with which to commence life in the real world.

Zev Chafets is a Fox News contributor. His latest book is "Remembering Who We Are: A Treasury of Conservative Commencement Addresses" (Sentinel 2015).