Money Talks, Moderation Walks: The Centripetal Impact of Campaign Contributions in the U.S. House

Do campaign contributions polarize legislators or induce moderation? Theory allows for both possibilities, with effects likely varying by donor type. Using data on all contributions received by members of the U.S. House of Representatives from 2001 to 2022, this paper examines how Political Action Committee (PAC) and individual donations affect subsequent roll-call voting behavior. The analysis focuses on within-legislator changes in ideological positioning across congressional terms. The results consistently show that increased contributions are associated with greater moderation on the economic dimension of roll-call voting. Republican legislators shift toward the political center following increases in both PAC and individual donations in the previous congress. Democratic legislators are more ideologically stable, exhibiting relatively modest centrist movement in response to higher levels of individual contributions. Dynamic specifications suggest that these associations accumulate over successive electoral cycles, most robustly for Republican PAC receipts. Additional analysis reveals a dimensional asymmetry: the centripetal pattern is specific to economic voting, while on the social dimension higher fundraising is if anything associated with more extreme positioning among Republicans. Overall, the findings suggest that campaign contributions in the contemporary U.S. House are associated with economic moderation rather than polarization.