Winning Coalition Formation in the U.S. Senate: The Effects of Legislative Decision Rules and Agenda Change

Recent empirical work has brought a renewed attention to the effect congressional rules of procedure have on the size of winning coalitions. Specifically, scholars have posited that legislative success hinges on the support of legislators identified by institutionally defined decision rules. Under these theories, supermajority decision rules in the U.S. Senate lead to larger, more inclusive coalitions on final passage. In this article, I reevaluate these claims by controlling for changes in the legislative agenda and the roll‐call voting record. I find that the aggregate size of winning coalitions is highly responsive to the underlying legislative agenda, the size of the Senate's majority party, and the manner in which researchers treat unrecorded votes. Further, my findings suggest that any connection between changes in the Senate's voting rules and the size of winning coalitions is spurious. Eric Schickler and Gregory J. Wawro have authored a response to this article, and Anthony J. Madonna has authored a rejoinder to this response. Both are available as Supporting Information .     

The Cost of Majority‐Party Bias: Amending Activity under Structured Rules

All major legislation in the House necessitates a special rule from the Rules Committee before it can be brought to the chamber floor. These rules often strictly limit floor amendments to bills considered by the House. Scholars of political parties have argued that the House majority party can bias policy output away from the floor median through its usage of restrictive rules. In this article, we argue that in order to secure the passage of restrictive rules, the majority often makes concessions to centrist legislators through the amending process. We examine this theory using a newly collected data set that includes all amendments considered by the Rules Committee during the construction of structured rules in the 109th, 110th, and 111th Congresses (2005–2010). Our results are mixed, but they do suggest that moderate members of the majority party often receive concessions via amendments for their support of the majority party's agenda‐setting regime.