Finding the Water’s Edge: When Negative Partisanship Influences Foreign Policy Attitudes

In moments of international crisis, US presidents have historically rallied public support by evoking the country’s national identity. Affective polarization undermines the salience of national identities and threatens to carry domestic divisions across the water’s edge. Does affective polarization reduce individuals’ support for military action? When is polarization most likely to extend beyond the water’s edge? I argue that the foreign policy consequences of affective polarization vary across intervention contexts and individuals. Using a series of ten survey experiments conducted during the 2016 presidential election season, I investigate the presence and stability of partisan gaps in support across security and humanitarian interventions. A second survey experiment directly manipulates negative partisanship, the president’s party affiliation, and the intervention scenario. The results indicate that negative partisanship can undermine the president’s ability to generate support for intervention, but context matters. Humanitarian interventions provide some insulation from the effects of affective polarization.