The Power of the Party: Conflict Expansion and the Agenda Diversity of Interest Groups

Abstract

To what extent do political parties have an effect on the policy-related activity of interest groups? Drawing from ideas of conflict expansion and the structure of extended party networks, we argue that political parties are able to pull interest groups into more policy conflicts than they otherwise would be involved in. We posit that parties are able to draw interest groups to be active outside of established issue niches. We suggest that several mechanisms—shared partisan electoral incentives, reciprocity, identification with the means, and cue-taking behavior—lead groups to participate in more diverse political conflicts. By linking data on interest group bill positions and the policy content of legislation, we generate a novel measure of 158 interest groups’ alignment with political parties. We find that the more an interest group is ideologically aligned with a political party, the more diverse their issue agenda becomes.