The tension created by the drop in violent crime since the 1990s and the sustained increase in mass incarceration in the American states during that period constitutes a phenomenon of great theoretical and policy relevance. Previous accounts of this tension centered on theories of group conflict and instrumentalism. We introduce a rhetorical framework for understanding mass incarceration. We argue that a key contributor to the mass incarceration boom is the use of aggressive political rhetoric by state governors to communicate the crime problem. Using data partially derived through content analysis of state of the state addresses of governors from all 50 states, we test this rhetoric theory and evaluate its implications alongside instrumental and conflict-based explanations of mass incarceration. Our analysis indicates that gubernatorial rhetoric has strong effect on mass incarceration but that this effect is moderated by the institutional power of the governor. Instrumentalism is not supported. The overriding implication of our findings is that mass incarceration is overwhelmingly a policy consequence of the punitive political rhetoric employed by state leaders to exploit the crime problem and mobilize political support.