Different Stages, Different Constituencies, Different Scores? Estimating Ideology Throughout the Campaign Cycle

Abstract

Campaign finance based ideological scores are widely used in political science to gain leverage on a number of important substantive questions. In this paper, we investigate the sensitivity of these scores to shifting strategic and competitive contexts associated with the transition from primary election campaigning to general election campaigning. We use campaign finance data made available by Bonica to create period-specific ideological scores for US House candidates between 2002 and 2018 election cycles. We find that candidates' ideological scores do change from the primary campaign to the general campaign, and that there are some systematic components to this within-candidate temporal variation. Specifically, we find that incumbents' scores are more stable than those of challengers or candidates running in open seat races. Finally, variation in ideological scores from the primary to the general election appears to be a function of the competitive context of the primary election. As the number of competitors in the primary election increases, so does the magnitude of the shift in the winning candidate's score from the primary to the general.