Scholars of the U.S. House disagree over the importance of political parties in organizing the legislative process. On the one hand, non-partisan theories stress how congressional organization serves members' non-partisan goals. On the other hand, partisan theories argue that the House is organized to serve the collective interests of the majority party. This book advances a partisan theory and presents a series of empirical tests of that theory's predictions (pitted against others). The evidence demonstrates that the majority party seizes agenda control at nearly every stage of the legislative process in order to prevent bills that the party dislikes from reaching the floor.
In Setting the Agenda, Cox and McCubbins argue for a concept they call the Procedural Cartel Theory, that the majority of the majority party functionally organize to distribute veto and proposal power within their party. Within the modern Congress, proposal power is generally consolidated amongst leadership positions (the Speaker, majority leader, whip, committee chairs, etc.) with veto power generally distributed (more members can say "no," that can effectively advance legislation). Cox and McCubbins offer that the most important legislative power is the party's ability to set the agenda (to determine what legislation is advanced to the floor for a vote).
There are important repercussions based on this theory. If the party leadership successfully controls which legislation ever makes it to the floor, then party voting discipline on the floor is less important (because the party leadership have already screened bills deemed unacceptable by the majority party).
Traditional findings about legislative process in the U.S. emphasized the floor of Congress, which means debate and vote after passage of committee. However, this book emphasized when senior members of the majority party determine which bills will be considered on the floor and which will not. The authors point out as the evidence Reed's rule introduced in 1890, which strengthen the power of senior members in the majority party in the legislative procedure, and the plunge of the roll rate of the majority party, which means how majority party are rolled, and so on. Especially, the difference between the roll rate before Reed's rule and after is clear and convincing.