Its first victory could also be the last gasp for a California bill to tax and regulate marijuana in the same way alcohol is controlled.
The state Assembly's public safety committee voted for the bill, 4-to-3, Tuesday.
But the health committee also must approve the measure by Friday before the full Assembly can consider it, an unlikely scenario.
The health committee is not considering the bill during its meeting Tuesday. And the bill's backers would have to get a special waiver to reconvene the health committee later this week.
If the bill does die, a spokesman for the bill's author, Assemblyman Tom Ammiano, said the San Francisco Democrat would hold off on reintroducing legislation until after the November election, which could feature a marijuana legalization ballot proposition.
Though the successful committee vote could end up being purely symbolic, pot advocates hailed it as an important step forward.
"We're thrilled," said Stephen Gutwillig of the Drug Policy Alliance, a pro-legalization group. "This to me, this is the formal beginning of the end of marijuana prohibition in the United States."
The legislation would allow adults 21 and older to legally possess, grow and sell marijuana. The state would charge a $50-per-ounce fee and a 9 percent tax on retail sales.
State tax collectors have estimated the bill could bring in nearly $1.4 billion in revenue.
Under the bill, much of that money would go to fund drug abuse education and prevention programs. Republican Assemblyman Danny Gilmore ridiculed that idea during the hearing at the state Capitol.
"We're going to legalize marijuana, we're going to tax it, and then we're going to educate our kids about the harms of drugs?" said Gilmore, a 31-year veteran of the California Highway Patrol. "You've got to be kidding me."
If the legislation fails to arrive on the Assembly floor this year, Gov. Arnold Schwarzenegger will likely not be forced to take a stand on marijuana legalization before he is termed out of office early next year.
At an appearance in Mountain View on Tuesday, he reiterated his support for debate on the issue, though he believes in the current law that makes the sale of marijuana illegal except for medical purposes.
The opinions of the state's politicians could be rendered moot in November, however, if voters approve a proposed ballot measure to legalize recreational marijuana under limited circumstances.
Oakland medical marijuana entrepreneur Richard Lee, the initiative's main backer, has said supporters have obtained far more than the necessary 434,000 signatures needed to qualify for the ballot.
The Tax and Regulate Cannabis 2010 campaign is expected to submit those signatures for approval later this month.
