Medicaid’s intergovernmental design with a generous federal matching rate and substantial state discretion has fostered gradual but steady expansions of the program over time. Gradual growth creates a favorable political environment in which each expansion creates a political constituency for Medicaid—among provider groups and enrollees—who then fight against retrenchment. Yet, as program expenditures continue to increase, especially during fiscally distressed times, the partisan divide over the future direction of Medicaid becomes more stark. These are the political dynamics that will define how states struggle with the Affordable Care Act (ACA) Medicaid expansion and also how states attempt to provide long-term care financing and services under their Medicaid programs.