In this report, we conduct original quantitative and qualitative analysis on the insurgence and influence of ideological PACs in primary elections to better understand how primaries exacerbate polarization. We demonstrate that ideological PACs surpassed business and labor groups as the most dominate interest groups in congressional primaries, and we described how these PACs are even less representative of the broader public than traditional interest groups. We show that ideological PACs employ more polarizing tactics and wield greater power than business and labor. Finally, we demonstrate that open, all-candidate primaries significantly mitigate the impact of ideological PACs.
Below, we summarize four key findings:
Representation: Ideological PACs are dramatically increasing their influence, even as they are increasingly advancing interests that are unrepresentative of Americans' views.
- In recent cycles, ideological PACs give 6-10 times more (controlling for inflation) than the once dominant business PACs gave before 2010.
- While business and labor organizations generally represent the interests of large segments of the U.S. population, ideological PACs generally represent the interests of a few wealthy individuals.
Extremism: Ideological PACs are more likely to support insurgent candidates challenging incumbents, and more likely to support more extreme candidates.
- Business and labor predominantly give to incumbents in primary elections, while ideological PACs mostly give to non-incumbents.
- Relatedly, ideological PACs are 2 to 6 times more likely than business and labor to support primary challengers.
- Ideological PACs give to more ideologically extreme primary candidates than business and labor.
Power: Ideological PACs wield more influence than business and labor PACs.
- When ideological PACs prefer different candidates from business and labor, the ideological PACs' preferred candidate is roughly four times more likely to win the primary.
- Since 2012, the number of ideological PACs who support a candidate is a better predictor of primary vote share than the number of business in labor and PACs.
Solution: — Open, all-candidate primaries significantly mitigate the outsized influence of ideological PACs.
- In open, all-candidate primaries, the impact of support from ideological PACs on a candidate's primary vote share is 1/4 as strong as it is in party primaries.
- In party primaries, backing from 20 ideological PACs (a one standard deviation increase) boosts a candidate's vote share by 9.4 percentage points.
- In open, all-candidate primaries, the same level of support only increases a candidates vote share by 2.4 percentage points.
