While patterns of intra-party conflict are important factor shaping party performance, it is surprisingly little studied in comparative party research. This paper addresses this gap by conceptualizing different types of conflicts, their respective consequences for organisational reform and evolution. While measuring the nature of conflict is notoriously difficult, party arbitration courts as legally required in German parties provide an ideal opportunity to map patterns of conflict. Consequently, the paper studies three German parties which underwent intense periods of conflict throughout their life cycles: The Greens, The Pirates and The Left. While they all stress member participation and qualify as new parties, they systematically differ in the level of centralization and the nature of participation structures (membership polls vs. delegate model). Our analysis shows that these differences constitute when conflict emerges, whether it is primarily driven by elites or members and how it affects the party’s internal evolution and external performance.
