Hannah Arendt was fearful not only of a populist President speaking in the name of the people and unbound by legality. She was also concerned that popular support could be harnessed by those responsible for limiting it. In other words, she was fearful of the American Supreme Court relying on popular support. This is the meaning of her obscure depiction of the American Supreme Court as “the true seat of authority in the American Republic” but unfit to power. I argue (...) that Arendt's characterization of authority as requiring “neither coercion nor persuasion” means that the Court's source of legitimacy is expertise rather than public support. Yet the current dominant understanding among American Justices as well as scholars is that public support is the source of the Court's authority. In Arendt's mind, such an understanding means that the Court has become the seat of power. The corruption of the Court's authority and constitutional law as a language of expertise capable of resisting public opinion will inevitably follow. (shrink)