Political parties are central to democratic politics, but where does the power lie within them, and how is it exercised? The Political Party in Canada explores the inner workings of these complex organizations through an examination of the composition and roles of party members and activists, candidates, local associations, donors, and central officials. The authors reveal the activities and power-sharing relationships that characterize Canadian parties, focusing not only on which groups are included in decision-making but on what authority rests with each level of their parties’ respective structures. This comprehensive examination opens a window on a fundamental institution that makes modern democracy possible.