This chapter examines the Supreme Court’s “precedent about precedent”—its doctrine regarding whether and when the Court may overturn its own prior constitutional decisions. Due largely to the influence of Justice Louis Brandeis in the early twentieth century, the role of stare decisis in the Court’s constitutional cases transformed from that of a vague common-law maxim to the status of contested doctrine. Using graphical “opinion maps” to trace the evolution of the Court’s case law on stare decisis, the author illustrates the division of stare decisis doctrine into two competing traditions: a “weak” tradition that allows overruling based on the supposedly faulty reasoning of a prior decision, and a “strong” tradition that demands some independent, non-merits-based justification for overruling. The author demonstrates that individual Justices frequently have aligned themselves with both traditions across different cases, and suggests that the force of the Court’s “precedent about precedent” is more rhetorical than constraining.