After the dispute gained national exposure — amplified by the professor’s appearance on Fox News, his op-ed in The Wall Street Journal, and right-leaning websites’ heaping derision on their newest college target — the professor, Bret Weinstein, said he had to stay away from campus for his own safety and move his family into hiding.

Student protesters briefly occupied the president’s office to press their complaints of racism on campus. In one encounter, the president, George Bridges, was recorded meekly complying with a demand not to use hand gestures when he spoke because they were threatening.

The campus has received threats of violence via social media and calls to the county sheriff and 911 that forced administrators to lock down the campus for three weekdays in a row. The college had another lockdown on Thursday, as dozens of professed free-speech defenders tangled with anarchists who were waiting for them at Red Square, the campus plaza named for its red-brick walkways.

“I thought I’d be speaking from Red Square where graduation is traditionally held, and then as the alt-right backlash hit us, I wondered if we’d have graduation at all,” Anne Fischel, a documentary filmmaker and Evergreen professor, said in her commencement speech on Friday. “No one should see this graduation as a return to normalcy, to the way things were before. For one thing, the lives of some of our community members have been threatened, and they can’t be here today.”

Since the presidential election in November, colleges from Middlebury to Auburn to the University of California, Berkeley have become swept up in a running battle over free speech and politics.