An organized campaign by groups such as the National Rifle Association has sought to convince policymakers and others that the Second Amendment to the US Constitution grants an unfettered right to individuals to possess any firearm, free from federal or state regulation. Although advocates may debate the meaning that should be given to the Second Amendment, under the American legal system the meaning of any particular constitutional provision is determined by the controlling precedent of Supreme Court cases. Two cases, Presser v Illinois and United States v Miller, remain the Supreme Court's latest word on the meaning of the Second Amendment. In Presser, the Court held that the Second Amendment is applicable only to federal, not state, laws. In Miller and subsequent federal cases, any Second Amendment "right" to bear arms is closely linked to the preservation of state militias, upholding a variety of federal gun legislation. Unless the Supreme Court modifies or reverses its Presser and Miller decisions, health advocates should understand that the Second Amendment poses no obstacle to even broad gun control legislation.