Last week, a group of anti-Israel protesters at San Francisco State University shouted down Jerusalem Mayor Nir Barkat as he was delivering a speech about, ironically, the challenges of leading a culturally and religiously diverse city.

The 40 or so protesters chanted so loudly that Barkat was forced to retreat to a corner where he attempted to speak to a similar-size group, mostly Jewish students, who wanted to hear what he had to say.

Treating the mayor, an invited guest of San Francisco Hillel, with such an outrageous lack of respect is one thing. But hiding behind the mantle of “free speech” to harass and silence someone with whom they disagree is a dangerous and growing trend that anti-Israel activists have been employing with false certitude on campus, taking advantage of a common misunderstanding of the First Amendment.

The constitutional right to freedom of speech allows individuals to express themselves without interference or constraint by the government. It does not give anyone the right to shut down another individual’s speech. That’s called bullying.

And the kind of bullying that has been increasing on our college campuses, especially in the Bay Area, targets one group: Jewish students, who are seen as representatives of Israel, proxies for the actions and policies of the country’s government and military. As such, they are considered fair game for insults, slurs, public humiliation and intimidation.

Students absolutely have the right to express their political opinions. But when, as has happened on other California campuses, holding signs calling for an end to the occupation gives rise to an atmosphere where swastikas are drawn on dorm walls and Jewish students running for student government can have their objectivity questioned, the university and the larger culture need to take a sharp look at what’s going on.

It’s not a slippery slope. It’s a leap off a cliff, straight down.

The University of California regents took an important step last month when they approved a resolution against intolerance. It states, among other things, that “anti-Semitic forms of anti-Zionism” will not be tolerated on any U.C. campus. That correctly distinguishes between political protest and hate speech. As detailed in our story this week, Jewish student groups are trying to pass a similar resolution at Stanford.

This should not be a Jewish issue alone. We call upon all right-thinking students, faculty members and administrators to stand up against all forms of hate on campus, including anti-Semitism.