A popular cause begins to gather steam. Originating from leftist activists, it attacks its target with unremitting focus and ferocity. The movement runs contrary to all available evidence when analyzed rationally, but it attains a sharp emotional resonance. It gains steam from social media algorithms juiced by foreign actors eager to promote division and advance their own preferred policies. It begins to break containment by attracting support in the center and even on parts of the Right. And it suddenly becomes mainstream, turning conventional wisdom on its head.