Police powers are the fundamental right of a government to make all necessary laws. In the United States, state police power comes from the Tenth Amendment to the Constitution, which gives states the rights and powers "not delegated to the United States." States are thus granted the power to establish and enforce laws protecting the welfare, safety, and health of the public.(1)
Police power is exercised by the legislative and executive branches of the various states through the enactment and enforcement of laws. States have the power to compel obedience to these laws through whatever measures they see fit, provided these measures do not infringe upon any of the rights protected by the United States Constitution or in the various state constitutions, and are not unreasonably arbitrary or oppressive. Methods of enforcement can include legal sanctions, physical means, and other forms of coercion and inducement. Controversies over the exercise of state police power can arise when exercise by state authorities conflicts with individual rights and freedoms.
The right of states to make laws governing safety, health, welfare, and morals is derived from the Tenth Amendment, which states, "The powers not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people." State legislatures exercise their police power by enacting statutes, and they also delegate much of their police power to counties, cities, towns, villages, and large boroughs within the state.
Police power does not specifically refer to the right of state and local government to create police forces, although the police power does include that right. Police power is also used as the basis for enacting a variety of substantive laws in such areas as Zoning, land use, fire and Building Codes, gambling, discrimination, parking, crime, licensing of professionals, liquor, motor vehicles, bicycles, nuisances, schooling, and sanitation. (2)
Hendrick v. Maryland 235 U.S. 610 (1915)
"The movement of motor vehicles over highways, being attended by constant and serious dangers to the public and also being abnormally destructive to the highways, is a proper subject of police regulation by the state.
In the absence of national legislation covering the subject, a state may prescribe uniform regulations necessary for safety and order in respect to operation of motor vehicles on its highways, including those moving in interstate commerce."
Hess v. Pawloski 274 US 352 (1927)
"Motor vehicles are dangerous machines; and, even when skillfully and carefully operated, their use is attended by serious dangers to persons and property. In the public interest the State may make and enforce regulations reasonably calculated to promote care on the part of all, residents and non-residents alike, who use its highways."
Reitz v. Mealey 314 US 33 (1941)
"The use of the public highways by motor vehicles, with its consequent dangers, renders the reasonableness and necessity of regulation apparent. The universal practice is to register ownership of automobiles and to license their drivers. Any appropriate means adopted by the states to insure competence and care on the part of its licensees and to protect others using the highway is consonant with due process."
Oklahoma City University Law Review, Vol. 30, p. 245, 2005
"Driving an automobile is a privilege, not a right, according to the prevailing laws of every jurisdiction of the United States."