Following the advent of the COVID-19 pandemic, analysts have noted a global rise of nationalism as countries have engaged in a number of nationalist moves in response to the pandemic. However, the implication of policy changes at the individual-level remains unclear: do citizens support those nationalist government responses? More importantly, do people tend to be more nationalistic following the outbreak? Building on terror management theory (TMT), this article examines whether and how ideological beliefs affect individuals' support for nationalist policies during the COVID-19 pandemic. According to TMT, to cope with death anxiety, people are predisposed to ideological defense, resulting in cohesion with individuals who validate their beliefs and hostility toward those who threaten them. Thus, we argue that when states' nationalist policies are aligned with their ideology, people tend to support them; yet, when states' nationalist policies contradict their ideology, people tend to withdraw their support. Specifically, this study found that as non-conservatives (compared to conservatives) are more concerned with the virus, they are more likely to show an inclination of ideological validation. Given that their ideology advocates more tolerance, nonconservatives are less likely to support nationalistic policies. To test the hypotheses, we applied structural equation modeling to a March 2020 CNN Poll (nationally representative US data about COVID-19). The statistical analysis demonstrated strong support for our arguments.