State Preemption Index (2026)

Preemption is the quiet force behind most “why doesn't my city just ban this” questions. When a state legislature passes a preemption statute, it reserves a subject for itself: cities and counties in that state cannot regulate it at all, or only within limits the state sets. The local ordinance you expect to find simply cannot exist, and a city council that passes one anyway will see it voided in court.

The pattern differs sharply by subject. Firearms are preempted in the large majority of states; minimum wage and paid leave in a substantial bloc; plastic-bag rules in about a dozen, where statutes forbid regulating “auxiliary containers.” Some preemption is old and settled, some was passed specifically to nullify one city's ordinance. The direction runs the other way too: solar-rights and right-to-farm statutes preempt local and private restrictions rather than local freedoms.

This index counts, per state, the state-tier rules in our corpus that explicitly bar or limit local regulation, so the score tracks documented statutes rather than reputation. Use the topic pages for the story within a single subject, and a state's own page for what its cities still may regulate.