State‐Level Political Institutions Matter: The Balance of Powers Among Governors, Legislatures, and Direct Democracy Influences Medicaid Expansion Decisions

Why have some Republican‐controlled states controlled expanded Medicaid while others have not? Research into state expansion decisions has emphasized partisanship, interest groups, legislative professionalization, and available resources. In contrast, we evaluate the impact of political institutions, which are rules that govern how officials reach policy decisions. We explain how different state institutional structures can lead to different expansion decisions, given similar partisan control patterns. We describe varying gubernatorial powers over Medicaid programs and analyze the potential of voter‐led initiatives to impose expansion on recalcitrant elected officials. Finally, we describe how politicians change rules to make it more likely that their preferences are enacted. Overall, focusing on institutions in addition to partisanship and interest groups more effectively illuminates the expansion prospects in holdout states. This allows for an effective illustration of potential roadmaps and roadblocks for pursuing both Medicaid expansion and other state‐level health reforms that can improve access and equity of health care .