# Police Power **Status: stub — expand.** The general authority of a state to legislate for public health, safety, morals, and welfare. It is the substantive content of what the [[Tenth Amendment]] reserves, and the structural reason the federal government is one of enumerated powers while states are not. Because it is a residual grant rather than an enumerated one, it needs no textual hook: criminal law, family law, property, professional licensing, land use, education, public health, and business regulation are all default state domains. Most law an American encounters is state law exercised under this power. It is limited from above by the [[Supremacy Clause]] and federal preemption, and from within by individual-rights guarantees applied to the states through the [[Fourteenth Amendment]]. *Jacobson v. Massachusetts* (1905) is the canonical public-health case; the COVID-era litigation and the post-[[Dobbs v. Jackson Women's Health Organization]] abortion regimes are the modern tests of its reach. ## See also - [[Tenth Amendment]] · [[Federal Preemption]] · [[Federalism Powers Crosswalk]]