SCOTUS Blog reports on part of the oral argument exchange:
Chief Justice Roberts several times questioned how the federal government could carry out uniform enforcement of the federal drug laws if states, on a theory of regulating the practice of medicine, were free to allow doctors to dispense controlled substances despite the federal law. Picking up on a hypothetical discussed by several Justices – that a state had opted to allow the use of morphine “to make people feel better” – Roberts asked rhetorically: “If one state allows the use of a drug that federal law says is illegal, how is the federal government supposed to enforce that prohibition?” . . . .
In addition, like some of the other Justices, seemed unpleasantly surprised when the state's lawyer, Atkinson, readily asserted when asked that the Attorney General could not interfere if a state allowed the use of morphine for recreational use, or of steroids for body-building.
The questioning, I think, shows an ignorance on the part of the justices about just how drugs are dealt within in a prescribed context in the United States. For example, morphine is used to make people feel better. Now, it is generally restricted to people who are believed to actually be in pain, but as any doctor will tell you, there are real limits to what medical science can do to determine who is in pain and how severe the pain is. Usually, patient self-reporting or past experience with other patients in similar situations is considered sufficient. Amphetamines, which include Meth, the current scourge of the drug wars, also have a variety of legtimate uses -- from treating ADD to helping Air Force pilots perform their missions better. Marijuana may not currently be prescribed for medical purposes, but few people outside the highly charged political world deny that it can be effective in treating nausea and pain in cancer patients. A great many of the states have through ballot measures or state legislation found that such legitimate medical uses do exist and should be authorized. Psychiatrists routinely prescribe anti-depressants to "make people feel better." What is so bad about that? Virtually all controlled substances do have legitimate medical uses, and there is nothing in the federal structure of the United States that supports that argument that the federal government should decide which uses of drugs are legitimate and which are not.
For decades, the prescription of alcohol for medicinal use during prohibition was derided as a sham. But, today we know that in fact regular moderate consumption of alcohol can dramatically reduce the risk of having a stroke or a heart attack.
The United States Code is not a religious text. Drugs are not banned because they are inherently evil. They are banned because they are believed to often lead to a course of addition and ruin for people who use them. But, there is little reason to believe that the same basis for banning drugs exists in the context of a state authorized and doctor supervised regime of drug prescriptions.