Explaining historical change is difficult because it involves analyzing a moving object. Historical explanations address this problem by dividing historical change into moments of discontinuity and periods of continuity. They explain discontinuities by retracing the generative processes that ultimately produced a change. Historical explanations explain continuities by drawing on path-dependent explanations. Such explanations involve specifying an early mover advantage during a historical discontinuity and following up by identifying so-called increasing return mechanisms that compound the causal effects of the early mover advantage over time. This compounding effect serves to epxlain why certain changes, once they are in place, reproduce themselves and hence endure.

This chapter uses process tracing to argue that organizations that grant voice and veto power to activists in the decision-making process avoid oligarchization of the party. The FA presents an opportunity to analyze how party organization per se affects the performance of political parties. The FA is a successful case of party building and reproduction that sheds light on the role organizational structure plays in reproducing activists. The process tracing systematically describes and explains the formation and reproduction of the party. It shows how the party´s first steps as a political organization established a reproduction mechanism with a lock-in effect that explains the persistence of the party’s activism.