RICHARD LEE, a marijuana entrepreneur, has in recent years turned part of Oakland into the cannabis capital of California and perhaps the world. Among his businesses is Oaksterdam University (a play on Amsterdam, where he got the idea), which teaches students all aspects of the weed, from the horticultural to the medical and legal, and has since spawned copycats elsewhere.

But this year Mr Lee wants to do more. He has sponsored a voter initiative, which has just been cleared for the November ballot, for the legalisation of marijuana in California. Adults would be allowed to own up to an ounce (28.5 grams) at a time for recreational use and could grow some in their homes. The state, its cities and its counties would be able to regulate and tax it.

If the measure passes—a poll last year found 56% in favour—California may once again lead the nation not only in usage but also in policy. Californian voters were the first, in 1996, to allow medical use of marijuana. Since then, 13 states and the District of Columbia have followed, and several more are considering it, including Arizona and South Dakota, both of which will also vote on the matter this year.

California's ballot measure would mark a new phase in decriminalisation, says Ethan Nadelmann, the founder of the Drug Policy Alliance, which lobbies for more enlightened drug laws. Why vilify or even lock up adults who wish simply to enjoy in moderation a substance no more toxic than alcohol, when you could instead tax and regulate the trade? It would help state budgets, which are in crisis. A tax-collecting agency in California, which confronts a $20 billion deficit, has estimated the potential revenues at more than $1 billion, plus savings from not locking people up.

That said, there would be legal hurdles. Since 1961 an international treaty has banned non-medical use of narcotic drugs, and America's federal law considers even medical use of cannabis a crime. But Eric Holder, America's attorney-general, last year signalled that cracking down on cannabis would not be one of his priorities. This suggests that marijuana could follow the path that alcohol took in the 1930s. Then, also during an economic crisis, the federal government stood back as the states relaxed Prohibition, until the 21st amendment officially ended it.