Electoral Competition and Special Interest Politics

We study the competition between two political parties for seats in a parliament. The parliament will set two types of policies: ideological and non-ideological. The parties have fixed positions on the ideological issues, but choose their non-ideological platforms to attract voters and campaign contributions. In this context, we ask: How do the equilibrium contributions from special interest groups influence the platforms of the parties? We show that each party is induced to behave as if it were maximizing a weighted sum of the aggregate welfares of informed voters and members of special interest groups. The party that is expected to win a majority of seats caters more to the special interests.