The traditional literature linking political parties and interest groups focuses on co-evolution (parties and interest groups compete for representing/mobilizing special interests), discipline (parties attempting to control who holds leadership positions in interest groups and vice versa); and brokerage (the formation of policy-driven coalitions among parties and interest groups). However, today politics is about major causes (secessionism; anti-austerity politics; immigration) shaping the political debate in terms of (pro- or anti-) identities. This provokes skyrocketing disturbances in the whole political system as there is an erosion of the traditional parties (and party systems), the emergence of new topics/demands, and the rise of new collective action legitimacies -political parties are no longer seen as the preferred channel of political participation-. In so doing, there is a somewhat realignment of not just political parties, now being more polarized, but also interest groups which are keen on getting involved in grand societal alliances. This leads to a vivid dynamic of organised/latent collective action that balances the forces between blocks, fostering the formation of new parties/coalitions and cause-seeking interest groups (and the alliances among them); a sense of permanent conflict around new identities that somehow goes beyond traditional socioeconomic cleavages (thus downplaying the power of traditional parties and interest groups); as well as the language of new social movements (we the people/ they the elites). The hypothesis is therefore that this new ‘identity/cause politics’ motivates increasing party outbidding and, as a result, the formation of distinct, separated party-groups blocks. To validate this hypothesis, we examine the case of Junts pel Sí in Catalonia, which is an hegemonic pro-independence coalition, and its close constellation of interest groups.
