Why do some party systems consolidate around a class cleavage, while a centre-periphery cleavage dominates other party systems? This dissertation examines how and why political parties survived the long democratization process of the 19th and early 20th centuries and how their variable survival shaped the cleavages present in party systems after universal suffrage. Using several original data sources and a mixed-method approach, I show that Socialist, Catholic, ethnic, and agrarian parties emerged slowly from below, and attempted to cement themselves in civil society through civic associations that provided members with necessary social services during a time of mass disenfranchisement from the emergent state. Some parties were more successful at this grassroots mobilization-through-social-services than others, however, and as a result, some parties survived into the democratic period while others did not. As incumbent parliamentary parties extended the franchise to new groups to protect themselves from rising parliamentary and extra-parliamentary threats throughout the long democratization process, the cleavage structure of the emergent party systems was determined by which of the grassroots movements and parties survived the democratizing period. Simply, where extra-parliamentary parties were able to and did form class-based constituencies through the provision of necessary goods and services during democratization, the party system came to be dominated by these issues post-universal male suffrage. The same can be said for national and religious identities and issues. By combining the study of incumbent party strategies and grassroots mobilization by excluded challengers, this work contributes to bridging together top-down and bottom-up theories of democratization, presents a theory for the persistence (or lack thereof) of parties through regime change, brings nationalism to the forefront of European democratization, and seeks to understand the origins of inter-group relations in diverse societies. Additionally, my work speaks to contemporary cases of voter enfranchisement and disenfranchisement, democratic backsliding, and the resurgence of nationalist illiberal politics in Europe.