This study analyzes the inner workings of the US House of Representatives in the post-World War II era. Re-evaluating the role of parties and committees, the authors view the political parties in the House - especially majority parties - as a species of legislative cartel . These cartels usurp the power, theoretically resident in the House, to make rules governing the structure and process of legislation. Possession of this rule-making power leads to two main consequences. Firstly, the legislative process in general, and the committee system in particular, is stacked in favour of majority party interests. Secondly, because the majority party has all the structural advantages, the key players in most legislative deals are members of that party and the majority party’s central agreements are facilitated by cartel rules and policed by the cartel’s leadership. Debunking prevailing arguments about the weakening of congressional parties, the study illuminates the ways in which parties exercise considerable discretion in organizing the House of Representatives to carry out its work.