In the United States, the COVID-19 pandemic became an unconventional vehicle to advance partisan rhetoric and antagonism. Using data available at the individual- (Study 1; N = 4,220), county- (Study 2; n = 3,046), and state-level (n = 49), we found that partisanship and political orientation was a robust and strong correlate of mask use. Political conservatism and Republican partisanship were related to downplaying the severity of COVID-19 and perceiving masks as being ineffective that, in turn, were related to lower mask use. In contrast, we found that counties with majority Democrat partisanship reported greater mask use, controlling for various socioeconomic and demographic factors. Lastly, states with strong cultural collectivism reported greater mask use while those with strong religiosity reported the opposite. States with greater Democrat partisanship and strong cultural collectivism subsequently reported lower COVID-19 deaths, mediated by greater mask use and lower COVID-19 cases, in the five months following the second wave of COVID-19 in the US during the Summer of 2020. Nonetheless, more than the majority for Democrats (91.58%), Republicans (77.52%), and third-party members (82.48%) reported using masks. Implications for findings are discussed.