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.