The US Supreme Court's decision this week asserting federal control over marijuana used for medical purposes would seem to bring that controversial practice to a halt. Uncle Sam - not the states - has the last word here, the court ruled.
But the 6-to-3 ruling may have raised more questions than it answered - and not just in the 10 states where medical marijuana has been legally used to treat the pain and nausea of certain illnesses.
For example, will the federal Controlled Substances Act now be enforced more rigorously?
Advocates on both sides of the issue say they do not expect to see US Drug Enforcement Administration (DEA) agents breaking down the doors and ripping up the plants of medical-marijuana users, especially if state and local cops - not obliged to help federal agencies prosecute people following state law - don't take part. Just a tiny fraction of the 750,000 pot busts made each year in the US are by DEA agents.
Will the ruling curb the number of states that allow medical marijuana? (The 10 that do are California, Alaska, Colorado, Hawaii, Washington, Montana, Nevada, Oregon, Vermont, and Maine.)
Polls show most Americans support medicinal use, including those opposed to general legalization of the drug.
For example, in a poll conducted last December for the American Association of Retired Persons (AARP), 72 percent of respondents aged 45 or older agreed that "adults should be allowed to legally use marijuana for medical purposes if a physician recommends it."
This can be seen as part of the general public belief that individuals - not government - should be in charge of their medical care, including end-of-life care as was at issue in the Terri Schiavo case.
That support is behind the push in several states to legalize the use of medical marijuana, provided a physician recommends it. The Connecticut Senate, for one, is considering a bill that would license medical doctors to certify the use of marijuana for certain debilitating conditions; patients would be allowed to grow up to four plants for personal use.
This week's court decision puts added pressure on Congress to deal with the issue. In writing the court's majority opinion, Associate Justice John Paul Stevens "stressed the need for medical marijuana patients to use the democratic process, putting the ball in Congress's court," says Rob Kampia, executive director of the Marijuana Policy Project in Washington, D.C.
"This is especially important now because next week, the US House of Representatives will vote on an amendment that would prevent the federal government from spending funds to interfere with state medical-marijuana laws," says Mr. Kampia, whose organization provided major funding for the case brought by two California women.
Another question raised by this week's ruling: What lies ahead for Oregon's unique physician-assisted suicide law? The US Justice Department says that law also violates the Controlled Substances Act, and the Supreme Court has agreed to take up the case this fall.
This week's decision also affects a broader debate on the drug. Some advocates had seen medicinal use as a vehicle for building support for marijuana legalization. The Bush administration firmly opposes such a move, and few lawmakers see political advantage in the debate.
But a report out last week estimates that replacing marijuana prohibition with a taxation and regulation system - as exists for alcohol - would produce combined savings and tax revenues of between $10 billion and $14 billion per year.
The report, by Jeffrey Miron, visiting professor of economics at Harvard University, has been endorsed by more than 500 economists, including well-known conservative Milton Friedman of the Hoover Institution at Stanford University.
In an open letter to President Bush, Congress, governors, and state legislatures, the economists call for "an open and honest debate," one they believe "will favor a regime in which marijuana is legal but taxed and regulated like other goods." Such a discussion "will force advocates of current policy to show that prohibition has benefits sufficient to justify the cost to taxpayers, foregone tax revenues, and numerous ancillary consequences that result from marijuana prohibition."
Still, there's no doubt that this week's ruling is affecting - at least for now - existing state programs and the more than 100,000 people they serve.
Oregon, for example, is temporarily halting issuance of medical-marijuana registration cards.
"We need to proceed cautiously until we understand the ramifications of this ruling," says state public health officer Grant Higginson, a physician who oversees the state's medical-marijuana program. "We have contacted the state attorney general to ask for a formal legal opinion."
While advocates of such programs view the ruling as a temporary setback, those who oppose them are encouraged.
Calvina Fay, executive director of the Drug Free America Foundation in St. Petersburg, Fla., calls it "an important victory for sound drug policy." Ms. Fay contends that many people falsely claim some medical problem in order to obtain the drug for recreational use.
Several medical organizations have advocated the use of marijuana for medical purposes. But the administration remains adamantly opposed, and it recently launched a new antimarijuana publicity campaign.
"Our national medical system relies on proven scientific research, not popular opinion," says White House drug czar John Walters. "To date, science and research have not determined that smoking a crude plant is safe or effective."