The “3.5 percent rule”—identified by political scientist Erica Chenoweth—should be on the lips of every American anxious about the Trump administration’s headlong drive to replace our democracy with authoritarianism. After studying more than 300 nonviolent resistance campaigns, Chenoweth and colleagues’ research revealed a startling truth: when just 3.5 percent of a population engages in sustained, strategic civil resistance, authoritarian regimes fall.