Law enforcement sources have told Fox News that there is a “99 percent” chance of violence on the campus of the University of California, Berkeley if conservative author and commentator Ann Coulter speaks on Thursday.

Once known as the home of the Free Speech Movement, UC Berkeley has become a virtual no-go zone for conservative speakers, from libertarian entrepreneur Peter Thiel (chased offstage by a mob in 2014), to gay conservative writer Milo Yiannopolous (shut down by riots in February). Berkeley administrators and police have refused to intervene to stop students and off-campus activists, and to protect the exercise of First Amendment rights.

Coulter was invited to speak by the Berkeley College Republicans, Young America’s Foundation (YAF), and a student dialogue group called BridgeCal. The event was set for April 27, but the UC Berkeley administration canceled the event. It offered alternative dates, ostensibly because they would be more manageable from a security standpoint. But Coulter refused to bow to the “heckler’s veto” — or, more accurately, “rioter’s veto” — over when she would speak.

Now, Coulter is planning to show up on campus Thursday regardless. She is expected to speak outdoors in Sproul Plaza, which is a designated free speech area on campus, and the site of the 1964 demonstrations that launched the Free Speech Movement. (No time has yet been set for the speech.) Fox reports that police are bracing for riots by leftists, anarchists, and so-called “anti-fascist” activists, whether or not Coulter actually appears on campus and tries to speak.

YAF and the Berkeley College Republicans are suing the university, and on Tuesday YAF withdrew its support for the Coulter event, citing the refusal of local law enforcement to protect participants. Berkeley’s mayor, 32-year-old Jesse Arreguin, expressed sympathy for the protests against Milo. He is also allegedly a member of the Facebook group of By Any Means Necessary (BAMN), a local left-wing militant group that has played a leading role in the unrest.

Joel B. Pollak is Senior Editor-at-Large at Breitbart News. He was named one of the “most influential” people in news media in 2016. He is the co-author of How Trump Won: The Inside Story of a Revolution, is available from Regnery. Follow him on Twitter at @joelpollak.