Politician’s ideology and campaign contributions from interest groups

This paper studies the effect of a politician’s ideological strength on campaign contributions that the politician receives from interest groups. If interest groups care mainly about current, or short-run, policy outcomes, they will make campaign contributions to ideologically neutral politicians who are often pivotal voters in the legislature. However, if interest groups care more about future, or long-run, policy outcomes, they have an incentive to help ideologically strong politicians who share similar policy preferences to win the election. Thus, liberal (conservative) interest groups will make campaign contributions to liberal (conservative, respectively) politicians. Using data on the amount of campaign contributions given by interest groups to the members of the US House of the Representatives in the 111th Congress (2009–2010), I show that ideologically neutral politicians receive more campaign contributions from interest groups. This result suggests that interest groups are primarily motivated by the short-run incentive.