Mapping Organizational Change in Southern European Parties: A Comparative Analysis of Mainstream and New Political Parties

The transformation of party politics in Southern Europe has brought into sharp relief the contrasts between traditional and emerging party organizational models. This paper provides a systematic comparison of organizational structures, decision-making processes, and membership patterns between established and new political parties in Italy, Spain, Greece, and Portugal since 2008. We analyze how new parties have departed from conventional party organizational templates that characterized traditional Southern European parties, particularly in terms of territorial presence, membership requirements, and internal power distribution. Through a comparative analysis drawing on party documents and primary data, we identify three key dimensions of organizational innovation: digital-based mobilization replacing traditional territorial structures, fluid membership models superseding formal party enrollment, and networked leadership structures challenging hierarchical party bureaucracies. Our findings illuminate how new political parties catalyze changes in party structures and reveal patterns of organizational hybridization. In addition, this analysis contributes to theoretical debates about party organizational adaptation and provides insights into the evolving relationship between party organization and democratic representation in Southern Europe.