Abstract This paper focuses on the question: Do persisting disagreements in constitutional interpretation affect the legitimacy of “the democratic system as a whole”? According to both Michelman and Waldron, the epistemic indeterminacy of interpretation—that is, the fact that principles do not possess stable meanings beyond, and independent of, their application to concrete cases—puts its finger on a point of the contractualist and prevailing political theory. But, if neither the legitimacy of any democratic order nor the standard of internal criticism can be founded on a broad background consensus on constitutional essentials, “what else makes a deliberative process of legislation and adjudication a generator of legitimacy so that citizens are induced to accept controversial results as ‘worthy of respect’?” The route pursued goes beyond all views that require legitimacy to be based on sharing a set of “thick” ethical beliefs. In this perspective, the author argues that the performative meaning of constitution-making “provides a thin yet sufficiently strong base,” which corresponds to the minimal requirements inherent in the very practice of framing a constitution.