With proponents arguing that it could put billions into state coffers and provide crucial jobs, California Democrats on Sunday will move to insert a plank in their party platform calling to “support the legalization, regulation and taxation of pot in a manner similar to that of tobacco or alcohol,” the Chronicle has learned.

The proposed platform change comes as 3,000 California Democrats met this weekend at a 3-day convention in Los Angeles, where they heard an appeal Saturday by Califonria Lt. Gov Gavin Newsom on the issue. The former San Francisco mayor argued to Democrats that — as with same sex marriage — the state should be leading, and not following, on a key issue which polls show now has gained marked support among Americans.

Newsom noted that while California lead the nation in 1996 in passing voter-approved Prop. 215 to support medical marijuana, it has now fallen behind other states, including Washington and Colorado, in moving to legalize the drug. He said that legalization would have a myriad of benefits that include boosting state revenue, diverting needed law enforcement resources and funding away from unnecessary incarceration.

“This is not a debate about stoners,” said Newsom. “You can be pro-regulation without being an advocate for drug use.”

Newsom’s comments appeared to reference remarks made by Gov. Jerry Brown, who said on NBC’s “Meet the Press”” recently that he was worried about the effects of too many people getting high on the drug.

Brown, in his comments, said he wanted to see how legalization would affect Colorado and Washington before supporting it in California. “How many people can get stoned and still have a great state or nation?” he asked. In a competitive and dangerous world, he said, “I think we need to stay alert, if not 24 hours a day, more than some of the potheads might be able to put together.”

But the proposed plank has the support of the major United Food and Commercial Workers Union, which already has 1,000 laborers in the medical marijuana industry — and is poised to represent potentially thousands more should pot become legal in California.

James Araby, executive director of the Western States Council of the United Food and Commercial Workers, , hailed the proposed state Democratic plank as “a good first step” in creating support and the groundwork for legislation for an industry “that has been growing for some time in California.”

Araby said the union supports a move to “create a regulatory framework in which the medical side can be regulated with a path to legalization,'” and potentially provide an economic boon to the state and to job creation.

“This industry is here,” said Araby, so it is now time to “legalize it and regulate it.”

A January CNN Poll showed soaring support for legalization of marijuana, with 55 percent of Americans now backing legal pot, compared to 44 percent opposed. The poll showed two third of Democrats now behind the idea, along with nearly 60 percent of independents — who now make up one in five voters in California — compared to just 36 percent of Republicans.

Colorado voters last year approved a 10 percent sales tax on marijuana, in addition to a 2.9 percent sales tax on all items sold in the state. The state has projected that sales of the drug could total $118 million in the next fiscal year — and that the legal market for cannabis could exceed more than half a billion dollars by 2015.