Abstract: We live in a time of anxiety about the rule of law. In railing against individual judges and their decisions, angry protesters—including elected officials and the President—presume a knowledge of what the Constitution requires, judicial pronouncements to the contrary notwithstanding. Recent bluster raises a question about what would occur if the President ordered government officials to defy a judicial ruling. The idea that the Supreme Court has ultimate authority in matters of constitutional interpretation—which often rides under the heading of “judicial supremacy”—has acquired strong currency. In the history of American political ideas, it has substantially eclipsed “departmentalist” theories, which hold that each branch of government should interpret the Constitution for itself, and an allied notion of “popular constitutionalism.” In the view of many, the rule of law requires judicial supremacy. This Article probes the concepts of judicial supremacy, departmentalism, popular constitutionalism, and the rule of law, all of which possess relatively timeless importance. In doing so, it sheds light on issues of immediate practical urgency. The truth, terrifyingly enough under current circumstances, is that our system is not, never has been, and probably never could be one of pure judicial supremacy. In principle, moreover, a regime in which judicial review operates within “politically constructed bounds”—and judicial rulings on constitutional issues are at risk of occasional defiance—is entirely compatible with rule-of-law ideals. In our current political context, there is abundant ground for anxiety about the future of rule-of-law constitutionalism. But judicial supremacy is not the answer to any significant legal, constitutional, or political problem. An adequate response will require repair of the ethical commitments—among elected officials and the public, as well as the Judicial Branch—that the rule of law requires.