The Other Side of Gridlock: Policy Stability and Supermajoritarianism in U.S. Lawmaking

Chapter 3 Pivotal Interval Movement

35 A scholar once declared, the merit of formal modeling is the “rigor and precision of argument that it requires” (Morrow 1994, 6). Although some political scientists equate formal theories to mathematical models, the raison d’être of formal theory should be centered on logical and deductive construction of causal theories. In fact, Niou and Ordeshook contend that the formal theories are “reactions to a discipline mired in imprecision, vagueness, obscure logic, ill-defined constructs, non-testable hypotheses, and ad hoc argument” (1999, 87). Nonetheless, several scholars complain about the seeming lack of empirical testing of formal theories (Palfrey 1991; Enelow and Morton 1993; Walt 1999; Morton 1999). Walt (1999) reminds students that the “only way to determine if a theory is truly useful is to compare its predictions against an appropriate body of evidence,” and he maintains that “a logically consistent but empirically false theory is of little value” (1999, 13). If the lack of empiricism in formal theories is substantial, what political science needs today are applied models that are easily connected to empirical models. Such applied models should logically and succinctly explain phenomena in the real world of politics and must generate hypotheses that are empirically testable. This chapter develops an applied model to explicate policy stability in lawmaking. The pivotal interval movement model is predicated upon the assumptions of supermajoritarian mechanism of Congress and nonpartisan voting behavior. Senate Rule XXII confers on senators the right to engage in extended debate, the so-called filibuster, subject to a cloture vote, which may Chapter 3 Pivotal Interval Movement The Other Side of Gridlock 36 be successfully invoked by sixty senators. This suggests that a minority (n–59) of leftist senators or rightist senators can block bills they dislike. Also, Article I, Section 7 of the Constitution grants the president the authority to veto legislation , which is subject to the congressional override by a two-thirds vote of the members present and voting in both the chambers. The predication is that one-third plus one members, whose preferences are close to the presidential preference, in either congressional chamber could reject unfavorable legislation. Thus, when the status quo policy is present within the so-called pivotal gridlock interval, which exists between the preferences of the 41st percentile senator (filibuster pivot) and 67th percentile legislator (veto pivot with an assumption of a conservative president), those bills that move the status quo leftward and rightward, respectively, will be blocked by 34 percent of legislators, who are conservative, and 41 percent of senators, who are liberal. The explanation above suggests that policies inside of the gridlock interval do not change (Krehbiel 1996, 1998; Brady and Volden 1998, 2006). More specifically, in this chapter, the pivotal interval movement model explains that the movement, rather than the width (Heitshusen and Young 2006; McCarty, Poole, and Rosenthal 2006, 177–84) or the change in width (Krehbiel 1998), of the gridlock interval would have an impact on policy stability. The model postulates that the gridlock interval of a current Congress becomes the status quo interval for the next Congress. In addition, the model introduces a concept, residuum, which is the portion of the gridlock interval of the previous Congress not overlapped by the gridlock interval of the new Congress. In this chapter, several core assumptions for the pivotal interval movement model are introduced. Second, the model is detailed and its hypothesis pertinent to policy stability is proposed. Third, the cartel agenda model (Cox and McCubbins 2002, 2005), as an alternative model, is explored. Last, the applied model of cartel interval movement is constructed, and its hypothesis is generated. Premises The model of pivotal interval movement is based upon several premises of congressional lawmaking. The central premises include exogenous shocks, policy space, preference, and supermajoritarian procedure. Exogenous Shocks The model of pivotal interval movement presumes that the positioning of the preferences of legislators, especially those of the veto and filibuster pivots, is Pivotal Interval Movement 37 vital to lawmaking. As Figure 3.1 illustrates, the distribution of legislators’ preferences could be determined by various exogenous shocks. These exogenous shocks include elections, influence of constituency on the incumbent legislators , and extreme events. First, elections change incumbent legislators, thereby altering the configuration of the member preferences in Congress. One of the most salient characteristics of congressional elections is the candidate-centered campaign (Herrnson 2004). In contrast to the party-centered campaign in most democracies...