The federal government can prevent sick patients from smoking home-grown marijuana a doctor recommended to relieve chronic pain, a divided US Supreme Court ruled last night.
The 6-3 ruling means the federal government can enforce a federal law prohibiting the cultivation, possession and use of medical marijuana even in the 10 states where it is legal under state law.
Justice John Paul Stevens said for the court majority that the federal law, the Controlled Substances Act of 1970, was a valid exercise of federal power by the US Congress "even as applied to the troubling facts of this case" involving two seriously ill California women.
Angel Raich has an inoperable brain tumour and other medical problems; Diane Monson suffers from severe back pain. Their doctors recommended marijuana for their pain.
"Just because we did not win this battle does not mean that we will not still have the opportunity to win this war," Ms Raich said.
She urged Congress to change the law to allow medical use of marijuana. "If I were to stop using cannabis unfortunately I would die," Ms Raich (39) said.
Justice Stevens said the question before the court was not whether it was wise to enforce the federal law in these circumstances, but only whether Congress has the power to adopt such a law.
He said the democratic process might be more important than the legal challenges and added that supporters of medical marijuana "may one day be heard in the halls of Congress".
It estimated as many as 100,000 Californians would use marijuana for medical purposes if the Supreme Court ruled for the two women.