Claremont McKenna College was once deliberately out of step with academic fashion. I used to tell prospective students and their parents, liberal or conservative, that one of the best things about CMC was that it refused to enforce the little catechism of political correctness. Regardless of political beliefs on campus, I assured them, students did not have to worry about speaking up in class or being persecuted for their opinions.

That is now very much in doubt. Last week the turmoil stirred at Yale and the University of Missouri swept my campus. A coalition of self-proclaimed “marginalized” students presented a catalog of “microaggressions” they had suffered, demanding new forms of “institutional support” in compensation. Demonstrators, who included both CMC undergrads and a few unfamiliar, skulking adults, denounced the dean of students and humiliated her in an open-air trial. Two students went on a hunger strike. Within days, Claremont McKenna—a place I have been proud to call my employer for more than three decades—surrendered ignominiously. How and why did it happen?

Founded in 1946 in a quiet town about 30 miles east of Los Angeles, Claremont McKenna College set out to make sense of a world shattered by depression, war and totalitarianism. The first classes consisted almost entirely of demobilized GIs from World War II, who found familiar the Quonset hut classrooms then in use. The school focused its curriculum on politics and economics, with a healthy skepticism about the latest New Deal-style nostrums and a high regard for the lessons of America’s constitutional experience.

Claremont McKenna never set out to be a true-blue conservative school. But it insisted that students hear conservative as well as liberal arguments, and its faculty eventually included some of the best students of Milton Friedman, James Buchanan and Leo Strauss. Their visibility, and the college’s promise to provide a genuine diversity, a diversity of reasonable ideas, meant that the college soon acquired a conservative reputation.

As the faculty expanded, however, it grew more hostile to the college’s original mission. The past two presidents encouraged the place to keep up with the spirit of the times. Now the examples of the University of Missouri and Yale have proved inspirational. Mizzou taught administrators that if they want to keep their jobs, they need to grovel early and often. Yale showed undergraduates that no matter how prestigious the college, the same rules applied, and that unloading F-bombs on professors, an act of incivility that once would have merited expulsion, is a trump card.

Unlike the hypothetical Halloween costumes that prompted the imbroglio at Yale, the dress-up that fanned the troubles at CMC actually happened. Two young women donned sombreros, ponchos and fake mustaches. A photo went up on someone’s Facebook page. Add this to a simmering controversy: After an aggrieved Mexican-American student complained that she felt out of place on campus, the dean of students wrote a poorly worded email pledging that the college was “working on how we can better serve students, especially those who don’t fit our CMC mold.”

On Nov. 10, Hiram Chodosh, CMC’s president, electrified the campus with an email saying he felt “very upset” about the Halloween-costume calamity. Remarkably, he called for a “sit-in in my office” to discuss things—perhaps the first time, as noted by historian Steven Hayward, that an administration ever called a sit-in to denounce itself. About 40 students showed up (of more than 1,200 in the student body). At 1:54 a.m. they emailed around a “Call to Action” with a list of demands and complaints of the students’ “feeling a strong pressure to assimilate and an inability to fully express their racial, ethnic, sexual, gender, and religious identity.”

That afternoon, President Chodosh replied with his own memo, announcing steps to satisfy the protesters, including two additional administrative positions on “diversity and inclusion”; a safe space to support new programming on the “campus climate”; “pro-active measures” to increase diversity in faculty hiring; and a “day of dialogue” in the spring, in preparation for which the administration “will provide in-depth facilitator training to faculty and staff in how to manage difficult conversations.” If not a complete embrace of the students’ demands, it came close.

Whatever the wisdom of his concessions, there was no disputing their efficiency. In 24 hours he agreed to measures that his administration had been discussing with the same students, it emerged, for seven months. Within 48 hours, the dean of students had resigned and a rump session of the faculty had issued its own statement calling for “diversity training for faculty,” ideally by next semester, and a thorough re-evaluation of the curriculum. The statement was quickly endorsed by 102 of my colleagues (a majority). I voted “no,” as did others, but somehow the dean of faculty did not report the number of those opposed.

The problem on campuses is that the elder members of the old New Left, and their spiritual descendants, are finding it impossible to object to the demands of the new New Left. In 1964 campus protesters kicked off the Free Speech Movement at Berkeley. Today’s students don’t have free speech high on their agenda, to put it mildly.

During the outdoor struggle session at CMC last week, an Asian student volunteered that she had once heard “go back to your home” shouted at her by a black person. “We should not distinguish people by their race or gender or anything. Black people can be racist,” she said. “I just mean that we have to look at people individually.” The crowd moaned disapproval and a young woman took back the bullhorn. Someone yelled that “racism is prejudice with power,” a shibboleth of the new New Left. Someone else shouted, “How is that relevant to the college failing to provide a space for people of color?”

That is what the protests are about: reordering campus in the name of the “marginalized” and their sponsors in the faculty and administration, whose turn has come to enjoy their own reign of intolerance. When the leftists lacked power, they embraced free speech. Now that they have power, they don’t need it.