We investigated if the COVID-19 pandemic’s onset caused changes in political attitudes. Influential theories predict that the pandemic’s onset will cause people to adopt more conservative attitudes, more culturally conservative attitudes, or more extreme attitudes. We comprehensively tested the external validity of these predictions by estimating the causal effect of the pandemic’s onset on 84 political attitudes and eight perceived threats using fine-grained repeated cross-sectional data (Study 1, N = 232,684) and panel data (Study 2, N = 552) collected in the United States. Although the pandemic’s onset caused feelings of threat, the onset only caused limited attitude change (six conservative shifts, four extremity shifts, 12 liberal shifts, 62 no change). Prominent theories of threat and politics did not make accurate predictions for this major societal threat. Our results highlight the necessity of testing psychological theories’ predictive powers in real-life circumstances.