Uncovering Evidence of Conditional Party Government: Reassessing Majority Party Influence in Congress and State Legislatures

This paper aims at enriching the debate over the measurement of majority party influence in con-temporary American legislatures. Our use of a new analytic technique, a grid-search program forcharacterizing the uncovered set, enables us to begin with a better model of legislative proceedings that abandons the simple one-dimensional spatial models in favor of the more realistic two-dimensional version. Our conclusions are based on the analysis of real-world data rather than on arguments about the relativemerits of different theoretic assumptions. Our analysis confirms that when legislators ’ preferences are polarized, outcomes will generally be closer to the majority party’s wishes, even if the majority-party leadership does nothing to influence the legislative process. This conclusion notwithstanding, our analysis also shows that at the margin of the majority party’s natural advantage, agenda setting by the majority party remains a viable and efficacious strategy. In the debate over party organizations in the Amer-ican Congress, one side (e.g., Aldrich and Rohde1998, 2001) argues that the majority party can in-fluence the outcome of legislative proceedings through agenda control or the ability to determine which pro-posals are considered. The other side (e.g., Krehbiel 1999, 2000) argues that agenda control conveys no power and that the majority party’s apparent influence stems from the fact that it has more elected member