Allocating Unlimited Money: What Explains Super PAC Spending in Congressional Elections?

Abstract

Abstract How do Super PACs allocate their resources? The question is both timely and relevant, particularly as we reflect on the ten-year anniversary of the Citizens United ruling. Super PACs now outspend – sometimes by huge margins, as in the 2016 presidential election – all other groups’ independent expenditures including those of parties, unions, and 501(c) organizations. The issue is especially important in congressional politics, where Super PACs have an opportunity to shape the institution every two years through congressional elections. Utilizing outside spending data from the Center for Responsive Politics, we analyze four U.S. House election cycles since the Supreme Court’s landmark 2010 Citizens United ruling (2012–2018). The likelihood that Super PACs invest in a race is strongly determined by the electoral context, even after controlling for the legislative influence of the incumbent member of Congress.