The decision overturned a lower court ruling that found the Oregon law illegally altered the relationship between the state and federal governments.
Tuesday's 6-3 decision found the federal Controlled Substances Act (1970), which prohibits the unauthorized dispensation of certain drugs, does not supersede Oregon's Death with Dignity Act, which exempts doctors who comply with specific safeguards from criminal liability in helping the terminally ill commit suicide. The law is the first of its kind in the nation and was upheld in a 1997 referendum.
In writing for the majority, Justice Anthony Kennedy said: "In the face of the CSA's silence on the practice of medicine generally and its recognition of state regulation of the medical profession, it is difficult to defend the attorney general's declaration that the statute impliedly criminalizes physician-assisted suicide."
Chief Justice John Roberts and Justices Antonin Scalia and Clarence Thomas disagreed. In writing his dissent, Scalia said: "The court's decision today is perhaps driven by a feeling that the subject of assisted suicide is not of the federal government's business. ... If the term 'legitimate medical purpose' has any meaning, it surely excludes the prescription of drugs to produce death."