By Nancy Murray and Sarah Wunsch

The Founding Fathers thought it was so important that they made it No. 1.

The former slave Frederick Douglass told a Boston crowd that liberty was meaningless without it.

Public Enemy rapped about it in “Fight the Power.”

Across the centuries, freedom of speech has been held up as a freedom worth fighting for. It is enshrined in the First Amendment.

How regrettable that it seems so little valued at the Massachusetts institutions where it should be most respected – our universities.

In late March, Boston College cancelled the appearance of University of Illinois professor William Ayers, a former member of the Weather Underground. He planned to speak about urban education.

A week later, the president of Clark University in Worcester cancelled a talk on “The Gaza Massacre” by former DePaul professor Norman Finkelstein.

At UMass-Amherst on March 11, Don Feder, a former Boston Herald columnist, cut short his speech after being repeatedly interrupted by the audience.

In all three cases, the First Amendment fell victim to the “heckler’s veto.” It is no less a threat to free speech than if someone yanked a microphone.

At BC and Clark, the hecklers were not in the room, but their pressure was just as effective.

When news of Ayers’ upcoming lecture was made public, a radio host asserted that the Weather Underground had been somehow linked to the killing of a Boston police officer in 1970. BC then caved in, saying it was canceling the talk out of “respect for the local community where the alleged actions of the Weather Underground continue to reverberate today.”

At Clark, President John Bassett was quoted in The Boston Globe as saying he cancelled Finkelstein’s speech because a Holocaust conference was taking place at the same time and Finkelstein’s presence “would invite controversy and not dialogue or understanding.”

Since when is “controversy” at odds with education? How ironic that such an excuse would be used to bar a speaker whose parents were both survivors of the Warsaw Ghetto and concentration camps.

At UMass, students shouted down Feder, apparently because they felt his speech on the “Myth of Hate Crimes” was meant to disparage what they deemed a recent campus hate crime.

The students had every right to show their dissent by turning their backs on the speaker, handing out leaflets or holding up signs, as indeed some of them did. They did not have the right to decide that only their viewpoint should be heard.

If freedom of speech is to mean anything, it must mean, in the words of Justice Oliver Wendell Holmes, “freedom for the thought we hate. ”

Nancy Murray is education director and Sarah Wunsch is an attorney with ACLU of Mass.