This investigation sought to examine the association between knowledge of the risks associated with environmental tobacco smoke and voter support for clean indoor air policies. In doing so, 2 antecedents were employed to enhance understanding of this relationship: attitudes and subjective norms. In addition, differences between nonsmokers and smokers were assessed across the aforementioned variables. The study sampled participants (N = 550) living in the Appalachian foothills as a means of conducting formative research prior to developing messages promoting clean indoor air policies. The study controlled for tobacco usage, age, biological sex, and income. Results revealed that awareness of risk is a good predictor of attitudes and social norms, and in return, attitudes and social norms are good predictors of support for clean indoor air policies. In addition, results reveal that nonsmokers maintain a significantly stronger belief in the dangers associated with environmental tobacco smoke, as well as more favorable attitudes, subjective norms, and support for clean indoor air policies when compared with smokers. These findings are discussed with a focus on message design strategies for practitioners and academics with interests in promoting clean indoor air policies.