Matthew Feldman, a professor at the University of York who studies right-wing extremism, said that November 3rd has all the hallmarks of being a potential “trigger moment.” He told me that polarization is growing on both sides, but he, too, believes that the far right represents a more lethal threat. “At the fringes on the right, a narrative is building that the left is stealing the election,” he said, warning that extremists may decide that “their way of life” will disappear “if they don’t take action.” But, he added, would-be attackers often await a signal from leaders that violence is acceptable. “Scholars have long talked about a kind of license that comes from the top,” Feldman told me. “One of the surest signs of these trigger events is an increasingly apocalyptic tone. And, of course, the biggest culprit has been Donald Trump.”