Last year, the San Francisco-based U.S. Court of Appeals for the 9th Circuit ruled 2 to 1 that [Diane Monson] was right. If the Supreme Court agrees, it could limit the federal government's power over not just the cultivation and use of marijuana, but also other activities.

Monson and her co-plaintiffs -- Angel McClary Raich, an Oakland woman who suffers from a variety of painful chronic disorders, and two people identified as John Doe One and John Doe Two, who give Raich pot free of charge -- argue that these recent cases favor them, because using small amounts of marijuana they grow for themselves, or passing it along for "compassionate" reasons, cannot affect the broader market for the drug.

In 2003, the court refused to hear the [Bush] administration's appeal of a 9th Circuit ruling that said doctors have a right to discuss marijuana as a treatment option with their patients. That left the 9th Circuit ruling on the books.