On February 1, 2017, Milo Yiannopoulos was scheduled to give a talk about free speech at the University of California, Berkeley. But he was prevented from speaking by a group of 150 or so masked, black-clad members of a then-obscure movement calling itself “Antifa.” The protestors caused $100,000 worth of damage to the campus and injured six people as they threw rocks and Molotov cocktails. Nine months later, again at Berkeley, an “anti-Marxist” rally descended into violence as approximately 100 masked Antifa members harassed journalists and beat rally organizers and attendees. Berkeley was where Antifa rose to national attention, but it hasn’t been the only place where the group has engaged in sustained acts of violence. At a Washington, D.C. Unite the Right rally in August 2018, Antifa members hurled objects at police and assaulted journalists. In Portland, Oregon, violent street clashes involving Antifa have become regular events. Notwithstanding claims that Antifa is a peaceful, “anti-fascist community-defense group,” it has adopted tactics that often are more violent than those of the right-wing movements that the …