Party Discipline in Elections and Latent Policy Ideals

Abstract

Individual politicians can have different policy preferences from their party leadership or special interest groups (SIGs), and the latter two may pressure politicians to shift their positions. To study this tension, we develop and estimate a multi-stage election model that incorporates discipline with election spending. First, we uncover the unobserved "ideal" policies of these different political agents. Second, we estimate disciplining constraints and the importance of "policy gaps" with candidates to parties and SIGs. We then study various dimensions of discipline: the conditions under which politicians become responsive to SIGs, the effects of seat competitiveness on disciplining, and the limits of discipline in the U.S. We find significant differences in policy ideals across party lines. We also find that a lack of electoral competition for a given Congressional seat makes discipline less effective and that voter preferences are more influential than party or SIG efforts in explaining candidate policy positions.