The Affordable Care Act (ACA) continues to be a contentious public policy. Yet, there is still much to learn about just how the ACA is impacting politics. Political scientists Michael Sances and Joshua Clinton will extend their previous RSF-funded research on the impact of the ACA’s Medicaid expansions on voter participation and public approval of the ACA. In this project, they will investigate the extent to which the passage of the ACA and its attempt to extend insurance to low-income residents through the Medicaid expansion affected political behavior and attitudes. They will compare the political behavior and attitudes of otherwise similar individuals (or counties or states, depending on the level of analysis) who differ primarily by whether they reside in a state that expanded Medicaid in order to identify how variation in the Medicaid expansion relates to differences in public opinion, vote choice, and the actions of elected officials.