The Constitution allocates public health powers among the federal government and the states. Federal public health powers include the authority to tax, spend, and regulate interstate commerce. These powers enable the federal government to raise revenues, allocate resources, economically penalize risk behavior, and broadly regulate in the public's interest. States have an inherent authority to protect, preserve, and promote the health, safety, morals, and general welfare of the people, termed police powers. Police powers enable states to preserve the public health in areas ranging from injury and disease prevention to sanitation, waste disposal, and environmental protection. The Rehnquist Court has emphasized the limits of federal powers and the primacy of states in public health issues affecting local concerns. Finally, the Constitution safeguards individual interests in autonomy, privacy, liberty, and property. The Supreme Court often defers to public health authorities in matters of public health, but engages in strict scrutiny if government interferes with fundamental freedoms or discriminates against a suspect class. Provided that they act justly and reasonably to avert a serious health threat, the Court should cede to agencies the power to act for the communal good. JAMA. 2000.