Judd R. Thornton

We examine if increased salience of partisan competition causes affective polarization in the United States during presidential elections. To do so, we leverage the random and quasi-random timing of survey interviews conducted during election campaigns. We conduct three separate studies. In Study 1, we utilize the 2008 National Annenberg Election Survey (NAES), in which random survey interview timing allows for a credible causal estimate of salience on affective polarization. In Study 2, we employ American National Election Studies (ANES) data from 1980 to 2016, again leveraging survey timing to assess the effect of salience on affective polarization. In Study 3, we examine changes in affective polarization as a result of increasingly salient partisan competition using NAES and ANES panel data from 1980 to 2008. Across the three studies we identify a meaningful increase in affective polarization toward candidates, but not toward parties, as a result of heightened partisan competition.