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

This study examines the relationship between Trumpism and COVID-19 vaccination in the US. We find that counties with greater Trump support show lower COVID-19 vaccination rates. However, this relationship is beyond the effects of Republican partisanship. The distinctive effects of Trumpism are further validated through falsification and placebo exercises. To address potential endogeneity, we suggest an instrumental variable (IV) strategy based on online search behavior before the rise of Trump. The IV estimates confirm the negative link between Trump support and COVID-19 vaccination, which is conditional on the partisan divide or conservative orientation. As a mechanism, we provide evidence that distrust in science increased to a greater degree in counties that voted for Trump in 2016 more than they did for Romney in 2012. Moreover, we do not find comparable results in places with an increase in Republican partisanship or conservatism. These results substantiate that the Trump effect on COVID-19 responses is not attributable to the general political climate.