Campus collisions over commencement speakers. Over-the-top public reaction to celebrity shockers. And genuine fear of physical reprisals over controversial issues.

Clearly, we’re a nation vigorously exercising our lungs as well as our rights.

Vigorous give-and-take in the “marketplace of ideas” is part and parcel of the First Amendment. The amendment’s 45 words protect our right to speak out, but certainly don’t mandate politeness in public comment or shelter those in that marketplace from less than full-throttle debate in the hope of changing minds or winning elections.

The U.S. Supreme Court over the years has reaffirmed our right to speak out even when it brings pain to others — at military funerals or by allowing Nazi-wannabes march through a predominately Jewish neighborhood near Chicago.

But we can go from “rights to wrong” — by preventing speakers from being heard simply because we oppose their views. By threatening harm rather than challenging ideas. And by trying to extinguish voices in place of speaking out ourselves.

William Bowen, former president of Princeton University, used his commencement speech at Haverford College just days ago to criticize a small group of students and professors who campaigned against the original speaker, Robert Birgeneau, former chancellor of the University of California, Berkeley. The critics attacked Birgeneau for his 2011 decisions in an incident involving police and student demonstrators.

Vocal protests and the threat of more led former Secret