In United States v. Windsor, the Supreme Court invalidated a key provision of the federal Defense of Marriage Act. In doing so, it raised significant questions about the power of states to limit the institution of marriage to opposite-sex couples. That issue was not presented in Windsor itself, but Windsor’s reasoning and rhetoric have already begun to play a pivotal role in ensuing challenges to state laws. Determining the future effects of Windsor, or of any other Supreme Court decision, requires defining the scope of judicial precedent. One account of precedent is restrictive: Only a court’s holdings must be followed in subsequent cases. Anything else the court says may be disregarded as dispensable dicta. But the restrictive account is fractured. It is fractured at the level of the Supreme Court, which commonly defers to broad reasoning and elaborate doctrinal frameworks. And it is fractured at the level of the lower courts, which candidly abide by Supreme Court dicta. These phenomena demonstrate the prevalence of a competing, inclusive paradigm of precedent in which a judicial decision’s constraining force has little to do with the classic distinction between holdings and dicta. This article examines the judiciary’s overtures toward an inclusive paradigm of precedent. It also draws out the sources of tension between the restrictive and inclusive paradigms to construct a framework for evaluating the use of precedent as a modality of legal reasoning. Finally, the article explains how the relative merit of each paradigm depends not on intuitions about holdings and dicta, but rather on deeper constitutional understandings, normative premises, and visions of the Supreme Court’s institutional role.