Historical Development of the Senate's Amendment Process

R Street Policy Study No. 111, September (2017).


In recent years, Senate majority leaders have utilized a complex assortment of rules and practices to exert greater control over the institution’s decision-making process than at any point in its history. The principal means by which they establish such control is their ability to block amendments on the Senate floor by filling the amendment tree. Despite the increased importance of the amendment process to the efforts of Senate majorities to control the agenda, we have, at best, only a limited understanding of how that process developed. This represents a significant limitation of the current literature given the increased controversy surrounding the practice of filling the amendment tree in the Senate today. This white paper fills in the gap in the current literature by considering key developments in the evolution of the Senate’s amendment process. Specifically, it focuses on the timing and sequence of changes in how amendments are considered on the Senate floor and the impact of such changes on the number of amendments simultaneously permitted on legislation. Examining the development of the Senate’s amendment process improves our understanding of the significant institutional change observed in that chamber represented by the rapid rise of the practice of filling the amendment tree.