This manuscript lays the groundwork for considering racial threat as a collective emotion. Although sociologists regularly study racial threat, a disconnect exists between Blumer’s theoretical framework (1958) and modern empirical measurement. Research has largely measured racial threat as perceptions of competition or increases in racism. Neither, however, squarely fits the symbolic interactionist framework that Blumer championed. This manuscript frames racial threat as an affective group response that is generated through sustained interaction with social groups and group representations. After showing how Blumer’s threat conceptualization fits the parameters of a collective emotion, I demonstrate how quantitative measurement and experimental research design can be used to capture threat as Blumer outlines it. Then, using factor analyses and regression, I illustrate that collective threat is distinct from other collective emotions and operates according to Blumer’s theoretical predictions. The manuscript concludes with a discussion of how ongoing attempts to measure collective threat and the evolution of racism in the United States highlight the continued relevance of Blumer’s work.