Ammiano's measure, AB 390, would essentially replicate the regulatory structure used for beer, wine and hard liquor, with taxed sales barred to anyone under 21.
He said it would actually boost public safety, keeping law enforcement focused on more serious crimes while keeping marijuana away from teenagers who can readily purchase black-market pot from peers.
The natural world would benefit, too, from the uprooting of environmentally destructive backcountry pot plantations that denude fragile ecosystems, Ammiano said.
But the biggest boon might be to the bottom line. By some estimates, California's pot crop is a $14-billion industry, putting it above vegetables ($5.7 billion) and grapes ($2.6 billion). If so, that could mean upward of $1 billion in tax revenue for the state each year.