STEVE INSKEEP, host:

The Supreme Court made a major ruling today on the medical use of marijuana. Even though some states have legalized medical marijuana, the court found that federal law trumps those efforts, and federal law enforcement authorities may now prosecute sick people who use marijuana even under a doctor's supervision. NPR legal affairs correspondent Nina Totenberg has been following this case and joins us now.

Good morning, Nina.

NINA TOTENBERG reporting:

Good morning, Steve.

INSKEEP: OK, 10 states legalized medical marijuana, and how exactly did this case get to the Supreme Court?

TOTENBERG: Well, this case is from California and there are two plaintiffs: Angel Raiche, who's a mother of two, as I recall, and has an inoperable brain tumor. She was in a wheelchair. She was really totally disabled and found the medical use of marijuana so helpful that she's now out of the wheelchair and able to sort of navigate her life. Diane Monson took it for pain, and there was a standoff in Diane Monson's yard where she was growing the marijuana where the local sheriffs defended her against federal authorities who were trying to arrest her and seize the plants.

Anyway, these two women sought an injunction in federal court barring federal authorities from going after them, and they argued that their activity was legal in California as it is, as you said, in nine other states. They won in the lower courts, but today the Supreme Court, by a 6-to-3 vote, ruled that the federal government was within its rights to prosecute them and other medical marijuana users.

Justice John Paul Stevens wrote the opinion for the court. He acknowledged that the case is very troublesome because, he said, `The plaintiffs have made out a good case, that they would suffer irreparable harm and that despite Congress' judgement to the contrary, marijuana does have a valid therapeutic purpose. But the question before the court,' said Stevens, `is not whether Congress acted wisely, but whether it had properly exercised its power under the Constitution. And,' said Stevens, `it is well settled law that the Congress in seeking to regulate or ban a commodity like marijuana acts rationally if it determines that it wants to have a complete ban and that would include at the state level. The federal law,' he said, `would have a gaping hole if medical marijuana use were permitted.' At least that's what the Congress determined and he said that was a rational determination.

INSKEEP: Now there are three justices who dissented here and it's interesting what they said, and also who they are.

TOTENBERG: Yeah, it's very interesting. The dissenters were the court's big states' righters, among the court's most conservative justices: Chief Justice Rehnquist, Justices O'Connor and Justice Thomas. Thomas wrote, `Angel Raiche and Diane Monson used marijuana that has never been bought or sold, has never crossed state lines, and has no demonstrable effect on the national market for marijuana. If Congress can regulate this, then it can certainly regulate anything and there are no constitutional limits to what the federal government can do.'

INSKEEP: So now we do have these patients who say that medical marijuana has helped them. Is there nothing that they can do?

TOTENBERG: Well, Justice Stevens in his dissent said the court was making no judgment on an argument that using marijuana is a medical necessity, and that they could, for example, use that if they're prosecuted at trial.

INSKEEP: They could defend themselves that way.

TOTENBERG: They could defend themselves by saying that this was a medical necessity. And this is obviously a road map for them to do that, but Stevens said the real recourse is to get Congress to change the law to allow states to legalize the medical use of marijuana. Oddly, you know, marijuana is, I think, by most people's agreement the least potent drug in terms of addiction and that kind of thing. It's not a great thing, but it's the least bad of the bad and it is categorized as the most serious.

INSKEEP: Nina, thanks very much.

TOTENBERG: Thank you, Steve.

INSKEEP: That's NPR's Nina Totenberg talking to us after the Supreme Court made its ruling today on the use of medical marijuana and the federal laws that do apply.

This is NPR News. Transcript provided by NPR, Copyright NPR.