The coronavirus pandemic provides a unique test of the limits of political partisanship and identity. In the current era of polarization, then, differences in partisan identity appear to influence a wide variety of social judgements and behaviours 16. Exacerbating these partisan differences, social media discourse has the potential to increase political polarization 13, 14, and slanted news outlets tangibly impact voting decisions 15. Furthermore, an estimated 81 million Americans reported arguing about politics with close friends and family after the 2016 election 11, and 34 million hours of Thanksgiving dinner conversation may have been lost in 2016 due to partisan differences between hosts and guests 12.
For instance, people’s choices of where to work, live, and shop are driven by political identity as much as they are by religion 8 partisan attachments distort memory for political events 9 and political homophily is as influential as educational homophily in online dating 10. Partisanship also substantially impacts behaviour 6, 7. People in the political minority are afraid to reveal their political identity 1, people view the opposing party more unfavourably than ever before 2, and partisan echo chambers abound both in person and online 3, 4, 5. Political partisanship has been on the rise in the United States and across the world. Taken together, these data suggest that US citizens’ responses to COVID-19 are subject to a deep-and consequential-partisan divide. Finally, the observed partisan differences in distancing were associated with subsequently higher COVID-19 infection and fatality growth rates in pro-Trump counties. Additionally, county-level consumption of conservative media (Fox News) was related to reduced physical distancing. Contrary to our predictions, the observed partisan gap strengthened over time and remained when stay-at-home orders were active. Partisanship was more strongly associated with physical distancing than numerous other factors, including counties’ COVID-19 cases, population density, median income, and racial and age demographics. Using the geotracking data of 15 million smartphones per day, we found that US counties that voted for Donald Trump (Republican) over Hillary Clinton (Democrat) in the 2016 presidential election exhibited 14% less physical distancing between March and May 2020. Numerous polls suggest that COVID-19 is a profoundly partisan issue in the United States.