By revealing the machinery and dynamics of the interplay between influencers, algorithms, and online crowds, DiResta vividly illustrates the way propagandists deliberately undermine belief in the fundamental legitimacy of institutions that make society work. This alternate system for shaping public opinion, unexamined until now, is rewriting the relationship between the people and their government in profound ways. It has become a force so shockingly effective that its destructive power seems limitless. Scientific proof is powerless in front of it. Democratic validity is bulldozed by it. Leaders are humiliated by it. But they need not be. With its deep insight into the power of propagandists to drive online crowds into battle—while bearing no responsibility for the consequences—Invisible Rulers not only predicts those consequences but offers ways for leaders to rapidly adapt and fight back.