The study of constitutionalism, and in particular of constitutional development, represents a significant recent turn in the field of public law. Constitutional development occurs, of course, through formal adoption and amendment. And the study of courts has established that judicial declarations contribute to this process. A growing body of scholarship also shows that the overtly political actors of society – legislatures, executive officers, political partisans, and even the people – continually engage in the informal creation, maintenance, and transformation of constitutional meaning.The growth in the study of constitutionalism and consti- tutional development in the last decade is reflected in a recent collection, Sotirios A. Barber and Robert P. George, ed., Constitutional Politics: Essays on Constitution Making, Maintenance, and Change (Princeton, NJ: Princeton University Press, 2001), as well as the following notable works: Bruce Ackerman, We the People: Transformations (Cambridge, MA: Harvard University Press, 1998); Stephen M. Griffin, American Constitutionalism: From Theory to Politics (Princeton, NJ: Princeton University Press, 1996); Wayne D. Moore, Constitutional Rights and Powers of the People (Princeton, NJ: Princeton University Press, 1996); Keith E. Whittington, Constitutional Construction: Divided Powers and Constitutional Meaning (Cambridge, MA Harvard University Press, 1999). While recent work illuminates instances of this latter type of constitutional development, there remain questions about the processes by which development occurs. Political actors create, maintain, and transform constitutional meaning, but the recent studies suggest that institutional contexts play an important role in shaping the consequent constitutional development. The very constitution that is subject to the forces of political actors, for example, also establishes an important, if not necessarily determinative, context that shapes the path of its continued development – consider that a government of separated powers, with its competing legislative, executive, and judicial branches, will facilitate conflicting efforts both to maintain existing and to construct new constitutional meaning.Ackerman, We the People; Whittington, Constitutional Construction. The works by Ackerman and Whittington demonstrate as well that the same effects follow from other features of constitutional design, such as Congress's bicameralism and the vertical separation of powers between national and state governments. Other institutions affect constitutional development as well. For example, social institutions exist alongside of and interact with political institutions. Through interactions, the former can enhance or undermine the stability of the latter. In this article, I argue that the study of constitutionalism must consider the full range of political and social institutions that shape constitutional development.

Although the concept of the “modern” presidency is not precisely defined in presidential studies, most scholars agree that a plebiscitary approach to executive leadership has dominated the American political landscape for much of the past century. The characteristics of this “plebiscitary presidency” include aggressive assertions of executive independence, direct appeals to the people, active manipulation of public opinion, and, binding all these together, a new emphasis on rhetorical prowess.Samuel Kernell, Going Public: New Strategies of Presidential Leadership (Washington, DC: CQ Press, 1997); Jeffrey Tulis, The Rhetorical Presidency (Princeton, NJ: Princeton University Press, 1987); Theodore Lowi, The Personal President (Ithaca, NY: Cornell University Press, 1985); Richard Rose, The Post-Modern President (Chatham, NJ: Chatham House Publishers, 1988); Ryan J. Barilleaux, The Post-Modern Presidency: The Office After Reagan (New York: Praeger, 1988). These characteristics are associated with enhanced resources for the exercise of leadership, but they stimulate, and sit in an uncertain balance with, a vast expansion of expectations for leadership.

One key problem concerning meaningful explanation of the activities of the United States Supreme Court is: how do the Justices make decisions in the cases before them? From the behavioralist perspective, attitudinalism remains the dominant model for explaining decision-making on the United States Supreme Court. A series of works uses statistical analysis, based on large datasets, to show clearly that the behavior of Justices, at least as far as their making of decisions in civil liberties cases goes, is highly predictable given a relatively small amount of information about the Justices' perceived views before their appointment to the Court.The availability and development of a major dataset – Harold J. Spaeth, United States Supreme Court Judicial Database, 1953–2001 Terms Computer File (East Lansing, MI: Program for Law and Judicial Politics, Dept. of Political Science, Michigan State University: continuously updated; downloadable from http://polisci. msu.edu//pljp) – has led to a series of increasingly comprehensive analyses of attitudinalism. See Jeffrey A. Segal and Albert D. Cover, “Ideological Values and the Votes of U.S. Supreme Court Justices,” American Political Science Review 83 (1989): 557–65; Jeffrey A. Segal and Harold J. Spaeth, The Supreme Court and the Attitudinal Model (Cambridge: Cambridge University Press, 1993); Jeffrey A. Segal et al., “Ideological Values and the Votes of U.S. Supreme Court Justices Revisited,” Journal of Politics 57 (1995): 812–23; Jeffrey A. Segal and Harold J. Spaeth, The Supreme Court and the Attitudinal Model Revisited (Cambridge: Cambridge University Press, 2002).

Institutions are instruments of stability. Twenty years of research in the “new institutionalism” has produced voluminous studies into how structures constitute or constrain the behavior of actors in political, social, and economic contexts. Agenda controls order and limit the alternatives actors choose from, logics of appropriateness dictate appropriate “scripts” agents follow in structural contexts, learning effects and high initial fixed costs reinforce past choices in ways that restrict future alternatives.Kenneth A. Shepsle, “Institutional Arrangements and Equilibrium in Multidimensional Voting Models,” American Journal of Political Science 23 (1979): 27–59; Paul J. DiMaggio and Walter W. Powell, “Introduction” in The New Institutionalism in Organizational Analysis, ed. Walter W. Powell and Paul J. DiMaggio (Chicago: The University of Chicago Press, 1991); Paul Pierson, “Increasing Returns, Path Dependence, and the Study of Politics,” American Political Science Review 94 (2000): 251–67. In other words, institutions produce stability through “regulative, normative, or cognitive mechanisms” that limit, constitute, or constrain the range of alternatives actors confront.Elisabeth S. Clemens and James M. Cook, “Politics and Institutionalism: Explaining Durability and Change,” Annual Review of Sociology 25 (1999): 441–66.

Adam Sheingate has made an important contribution to the literature on political entrepreneurship. He takes a concept that has been widely but casually employed by political scientists studying institutions and policies and sets out to supply that concept with clarity and content. Appropriating the concept for historical institutionalism, he connects the role of the political entrepreneur to the processes of institutional change, posing a powerful challenge to the familiar view of institutions in equilibrium. Especially important for readers of this journal, he expands upon previous uses of the concept by arguing that it offers a new vantage point on American political development, with political entrepreneurs posited to be critical sources of endogenous change.