In Canadian politics, a leadership convention is held by a political party when the party needs to choose a leader due to a vacancy or a challenge to the incumbent leader.
In Canada, the leader of a party generally remains that party's de facto candidate for Prime Minister until such time as he or she dies, resigns or is dismissed by the party. In the New Democratic Party and some of its provincial branches, the position of party leader was treated as all other positions on the party's executive committee, and open for election at party conventions generally held every two years, although incumbent leaders rarely face more than token opposition.
In the United States, a political party committee is an organization, officially affiliated with a political party and registered with the Federal Elections Commission (FEC), which raises and spends money for political campaigning. Political party committees are distinct from political action committees, which are formally independent of political parties and subject to different rules.
Though their own internal rules differ, the two major political parties (Democrats and Republicans) have essentially parallel sets of committees. (Third parties have varied organizational structures, although several do have national committees officially recognized by the FEC.)