There is currently a resurgence of interest in political parties. This resurgent interest embraces a minimalist definition of political party, according to which any group that competes in elections and receives a handful of votes qualifies as a party. Parties, however, are expected to contribute to democratic representation, and the party politics literature has extensively shown that many “parties” do not fulfill this expectation. Entities that exhibit some but not all of the features that define political parties can be considered diminished subtypes of the category. A thorough conceptualization of diminished subtypes could improve the analytical value of the study of political parties and of other forms of electoral political organizations. In this introduction to the edited volume, we propose a new political party typology that includes diminished subtypes. The typology is based on the presence or absence of two primary attributes: horizontal coordination of ambitious politicians during electoral campaigns and while in office and vertical aggregation to electorally mobilize collective interests and to intermediate and channel collective demands.