or as applied in any of these cases. We doubt that it is well situated to do so in the future. Leaving such inconveniences aside, the embrace of a universal formal theory of congressional action would be wrongheaded in any event. In our view of the state of political science, no theory of legislative decisionmaking exists that is capable of addressing the issues adequately. For example, positive political theories of legislative politics, which extend well beyond public choice theory of the 1960s and 1970s, have become an important branch of legislative scholarship in political science. 3 Positive political theories treat legislators as instrumentalist and, given a set of assumptions about the rules or institutional setting in which they operate, deduce propositions about legislators' behavior, institutional choices, or policy outcomes. There are a variety of positive theories of legislative politics, however. They differ in assumptions about the political motivations of legislators (policy, reelection, or progressive ambition) and about the identity of other players relevant to goal achievement (the President, interest groups, the electorate, the courts, and so on). They also differ in what they seek to explain (individual voting behavior, the structure of committees and parties, or policy outcomes). Simply stated, there is no single positive political theory of legislative decisionmaking. Rather, a variety of theories have emerged to address various aspects of legislative politics. Our approach reflects this state of affairs in the theory of legislative decisionmaking.' 4 While there is reason to believe that members are at least partly instrumental, it is unwise for us, or the courts, to attribute any particular motivation to members of Congress. There is no basis, as a general rule, to assume that interest groups, the electorate, parties, or any other political actors dominate the legislative process. In the absence of a single theoretical standard for evaluating the Court's treatment of the legislative process, we turn to the more burdensome, but 112. For example, Bill Eskridge's study of instances in which Congress has overridden Supreme Court decisions by statute found that states were among the most successful petitioners for such congressional action, William N. Eskridge, Jr., Overriding Supreme Court Statutory Interpretation Decisions, 101 YALE L.J. 331, 348-49 (1991). 113. See, e.g., Symposium, Positive Political Theory and Public Law, 80 GEO. L.J. 457 (1992). 114. See, e.g., Kenneth A. Shepsle & Barry R. Weingast, Positive Theories of Congressional Institutions, in POSITIVE THEORIES OF CONGRESSIONAL INSTITUTIONS 5 (Kenneth A. Shepsle & Barry R. Weingast eds., 1995). Imaged with the Permission of Yale Law Journal [Vol. Ill: 1707 1730 HeinOnline -111 Yale L.J. 173