Several authors have emphasized two main characteristics of outsider parties: on the one hand, they rely on a protest component; on the other, they share a populist appeal. Both elements are crucial to gain electoral support to the detriment of mainstream parties. Yet, in order to guarantee their survival, they have to build stable linkages with specific sectors of civil society through symbolic and organizational tools. This study examines to what extent radical left parties may benefit from returning to grassroots social forces, namely by allying with social movements and organized interests. The paper aims to explore this argument by considering a case-study based on the Portuguese Left Bloc, a recently created left-libertarian party which has experienced a notable increase in its electoral support during the last decade. To examine the relationship between society and radical left parties this study will focus on the mobilization strategy of the Left Bloc by investigating three related dimensions. The first deals with the social function traditionally performed by political parties. This means to analyse to what extent civil society is an important tool to organize grassroots activities and disseminate party’s causes. The second dimension refers to human resources at both the mass and elite level. The profile of party members and leaders is a useful indicator of the representation of specific groups. Finally, the third dimension is based on policy orientations and identity politics. Radical left parties have been particularly successful when they have been able to give expression to the need of recognition of particularistic demands based on gender, sexuality or socio-economic marginality. The paper argues that the relationship between society and radical left parties is crucial for understanding their institutionalization and electoral success, although it may create also future constraints in terms of intra-party dynamics and party strategy.
