Unlike Jonathan, I am unpersuaded that the Supreme Court’s 6-3 opinion in Gonzales v. Oregon reached the right result. The question is a complicated one, and there are folks on the other side (like Jonathan and Nelson Lund) whose judgment I respect, but it seems to me that federal definition of what constitutes a “legitimate medical purpose” is essential to the effectiveness of the comprehensive federal scheme that the Controlled Substances Act creates. On first read at least, I don’t see how the majority has a principled approach that would distinguish Oregon’s law from a state law that authorized doctors to prescribe morphine. (Scalia’s dissent charges that the majority “reverse-engineers” its approach.)
One related point: Lots of folks supporting Oregon, including those ordinarily hostile to robust state powers, have invoked “federalism” as though it were some free-floating principle that trumps federal power. The Court majority itself, in a strange passage on page 6, seems to suggest that AG Ashcroft violated some etiquette of federalism by not consulting with the Oregon AG before issuing his interpretive rule. But federalism interests arise in different contexts and have varying force, and they would appear to be at their weakest in the context of a comprehensive federal scheme to combat controlled substances.