Oppression and inequality, as critical social and structural determinants of health, are key threats to public health. Democratic stability provides institutional measures to mitigate oppression and inequality. We investigate trends in democratic backsliding in the Organization for Economic Co‐operation and Development (OECD) nations, overall, and compare trends in backsliding among specific indicators of democracy relevant to public health based on protections against oppression and inequality. We leverage a comprehensive, longitudinal, data set (V‐DEM), capturing key indicators of democracy in OECD nations from 2010 to 2020. Indicators were selected from the scholarly literature on democracy and health for their effects on oppression and inequality. We observe trends over time in democratic stability among OECD nations, overall, and then compare trends in democratic stability or backsliding across OECD nations within categories of democratic indicators established to mitigate oppression and inequality. Democracy is declining across all OECD nations. Broad democratic declines are shown between types of OECD member states. Country income is not necessarily protective for democratic stability. We find specific declines in two measures with immediate implications for public health—Civil Liberties and Integrity of the Courts—across at least half of all OECD nations and a particularly alarming level of change in the United States. Politics shape and limit public health. Declining components of democracy can have both short‐ and long‐term consequences for population health by increasing inequality and reducing mechanisms to protect against oppressive tactics. Public health can play an important role in improving democracy by strengthening accountability.