WASHINGTON — On some of the nation’s college campuses, a culture of sanitized conversations and sensitivity, reinforced by the polarization in contemporary American society, has caused an uptick in the suppression of free speech, several experts say.

Lecturers have been blocked and in some cases assaulted by crowds of protesters who disagree with their views.

In one incident at Middlebury University in Vermont, violent student protesters shut down a lecture by conservative author Charles Murray and injured a Middlebury professor who was with him.

At Kellogg Community College in Michigan, students were thrown in jail for seven hours for handing out copies of the Constitution in an open area outside the performing arts center, as freedom of expression like that is permitted in only one location on campus.

This new campus climate features such terms as “microaggressions,” which Rutgers University defines as “brief and commonplace remarks that, whether intentional or unintentional, could hurt someone else’s feelings based on their affiliation with a particular group.”

Issues that may be important to discuss in the classroom are getting sidelined because they could hurt someone’s feelings.

“The kids that are in college now grew up dipped in Purell,” filmmaker and comedian Adam Carolla said. “We’ve got to be the adults here. If you take people and put them in a zero-gravity environment, they are going to lose muscle mass. Children—our college students—must be exposed to germs and dirt. Their plan is to put them into a bubble.”

Experts say that some students insist that their universities are not entitled to allow speakers with “offensive messages” to speak .

“With microaggression, words are seen as violence, said Ben Shapiro, editor in chief of the Daily Wire. “Students are told by ideologues that the validity of an argument is judged solely by identity, and often that the best response is macroaggression—physical violence.”

Postmodernism, or the system of related disciplines holding all truths to be relative, all knowledge constructed and all hierarchies insubstantial, and the identity politics that often reinforces it, is cited by some as being symptomatic of the problem.

“Part of the problem is Postmodernism, said Dr. Michael Zimmerman, former vice president for academic affairs for Evergreen State College. “One possibility is the relentless disparagement that the Critical Theory disciplines have historically had vis-a-vis STEM or Science, Technology, Engineering, and Math. Faulty members need to hold their colleagues accountable and encourage civil discussion. Many faculty have chosen to censor themselves.”

A law was recently passed by the Wisconsin state legislature that punishes students for engaging in this type of behavior against speakers.

Government intervention is not always the preferred response to the problem, though, said Frederick Lawrence, national commissioner of the Anti-Defamation League. University presidents often prefer to have the discretion to work within existing laws.

When delivering lectures on the subject, NYU law professor and free speech expert Nadine Strossen said she often cites the words of former Brown University President Ruth Simmons, ‘I believe that learning at its best is the antithesis of comfort.’”