In the United States, preemption is a legal doctrine that allows upper levels of government to restrict or even prevent a lower-level government from self-regulating. While it is often thought of in the context of the federal government preventing state regulation, preemption is increasingly used as a tool by states to limit cities, counties, and other lower-level municipalities from legislating across a broad array of issues.
The extent of a state’s ability to preempt local government depends on a variety of factors. These include whether the state grants local governments the power to govern (known as home rule) or whether the state follows Dillon’s Rule, which only permits local governments to legislate where a state has expressly allowed. Additionally, the type of preemption and the discretion of local government varies across and within states and from topic to topic.
This map identifies key features of state-level preemption laws in 50 states, from August 1, 2019, to November 1, 2021. The dataset captures both express preemption contained in constitutional provisions and statutes, and implied preemption identified in case law and attorneys' general opinions. Specifically, the data displayed here examine state-level preemption in 12 domains that impact the social determinants of health: (1) Ban the Box, (2) firearms, (3) mandatory inclusionary zoning, (4) municipal broadband, (5) mandatory paid leave, (6) rent control, (7) full disclosure tax requirements, (8) general revenue limits, (9) general expenditure limits, (10) property tax rate limits, (11) tax assessment limits, and (12) tax levy limits.