Trump vs. the GOP: Political Determinants of COVID-19 Vaccination

This study examines political determinants of COVID-19 vaccination in the US, focused on the distinction between Republican partisanship and Trumpism. We find a negative relationship between Trump support and COVID-19 vaccination rate across counties beyond the partisan divide in the pandemic response. The distinctive effects of Trumpism are further validated through falsification and placebo exercises. To sharpen identification, we use an instrumental variable (IV) strategy based on online search behavior, which confirms the negative link between Trump support and COVID-19 vaccination. Related to a potential mechanism, we conduct an exercise using attitudes toward climate change, whose relationship to Trumpism is considered to be analogous to that of views on COVID science. The results suggest that skepticism about global warming increased to a greater degree in counties that voted for Trump more than they did for Romney. We do not find comparable patterns in places with an increase in Republican partisanship or conservatism, which suggests that the Trump effect on COVID-19 response is not attributable to the general political climate.