In supporting the invocation of stare decisis in constitutional cases, the Supreme Court has maintained that its decisions affect how the people conceptualize the government and their rights. Such an argument, which prioritizes contemporary understandings of the Constitution over both the intentions of Framers and the nuances of doctrine, suggests that constitutional decisions may affect the meaning of the Constitution itself. In this Article, Professor Abramowicz offers a positive account demonstrating that the Court has used this type of argument, which he dubs "constitutional circularity," and provides a normative critique. The positive account is relevant not only because it identifies a type of reasoning that scholars have not explored, but also because it undermines contentions by recent commentators that stare decisis is a matter of policy even in constitutional cases and therefore subject to abrogation by Congress. Normatively, constitutional circularity presents the danger that judges will find their preferences in alleged popular understandings of the Constitution, but given the indeterminacy of constitutional law, constitutional circularity need not exacerbate this problem of judicial lawmaking. At the same time, the notion of constitutional circularity reflects and may reform several areas of constitutional doctrine and strands of constitutional theory.