Conventional wisdom is that outside the Eighth Amendment, the Supreme Court does not engage in the sort of explicitly majoritarian state nose-counting for which the “evolving standards of decency” doctrine is famous. Yet this impression is simply inaccurate. Across a stunning variety of civil liberties contexts, the Court routinely—and explicitly—determines constitutional protection based on whether a majority of states agree with it. This Article examines the Supreme Court’s reliance on the majority position of the states to identify and apply constitutional norms, and then turns to the qualifications, explanations, and implications of state polling as a larger doctrinal phenomenon. While the past few years have seen an explosion of constitutional law scholarship demonstrating the Supreme Court’s majoritarian tendencies, the most powerful evidence of the Court’s inherently majoritarian nature has been right under our noses all along: its widespread use of explicitly majoritarian doctrine.