This book is devoted to an exploration of two closely interrelated questions. First, under what conditions is the creation of a legitimate constitutional regime possible? Second, what must be true about a constitution if the regime that it grounds is to retain its claim to legitimacy?

The focus on legitimacy derives from the fact that a constitution is fundamentally an instrument of legitimation for a set of juridical practices. By the term “juridical” I mean the combination of legal, political, and administrative actions that are undertaken in terms of laws or law-like rules as elements of formal institutions of governance. A constitutional regime is one in which the claim to legitimacy of these juridical practices rests, at least in part, on a prior claim of legitimacy on behalf of a constitution. This is not to say that the constitutional and legal claims of authority are coextensional; the relationship between a constitution and ordinary law will be the subject of a great deal of discussion in later chapters. But describing a system as a “constitutional regime” implies that the system of institutional organization and a set of basic guiding norms are authoritatively contained in the constitutional “text,” however conceived. As a result, I will conceive of a constitutional system as one that has two critical elements: institutionalized mechanisms for collective action, and a set of law-like rules supreme within their domain. For a constitutional regime to be legitimate, each of these elements requires an adequate justification.