Voters on Tuesday approved Proposition 64, an initiative that will make California the most populous state in the nation to legalize the recreational use of marijuana, setting state officials in motion to build a massive retail sales system to accommodate the new law.

The ballot measure was buoyed by a flood of $16 million in campaign cash from supporters including former Facebook President Sean Parker.

The approval of the ballot measure would create the largest market for marijuana products in the U.S. It comes six years after California voters narrowly rejected a similar measure. Activists lauded the expected passage as an important moment in a fight for marijuana legalization across the U.S.

“Proposition 64 will allow California to take its rightful place as the center of cannabis innovation, research and development,” said Nate Bradley, executive director of the California Cannabis Industry Assn.


The initiative allows Californians who are 21 and older to possess, transport and buy up to 28.5 grams of marijuana and to use it for recreational purposes. That expands the law that 20 years ago legalized marijuana for medical use in California.

California is the largest of five states that were considering the legalization of recreational marijuana use Tuesday and approval here was seen as a milestone in the effort to end prohibition of pot nationwide. Another four states — Colorado, Washington, Oregon and Alaska — have previously legalized pot.

“I think it’s the beginning of the end of the war on marijuana in the United States,” said Lt. Gov. Gavin Newsom, who was the leading voice of the campaign. “I think it will have repercussions internationally, particularly in Mexico and Latin America. And there are a million people who tomorrow can begin the process of clearing their records.”


The new California initiative would allow adults to grow as many as six plants for personal use. In addition, the ballot measure allows retail sales of marijuana by licensed shops and imposes a 15% excise tax.

Although the measure’s passage would immediately allow adults to possess and grow marijuana, there may not be places to legally purchase it for some time.

The measure only allows non-medical marijuana to be sold by state licensed businesses, and it gives the state until Jan. 1, 2018, to begin issuing sales licenses for recreational retailers.

The approval of Proposition 64 sets off a scramble by state agencies, law enforcement, university researchers and local governments to prepare California for a system that allows people to legally buy and use recreational marijuana.


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“We’re in a period of massive transformation in cannabis policy,” said Assemblyman Rob Bonta (D-Oakland), a leading lawmaker on marijuana issues.

The issue of when people can legally buy marijuana is one that the state Legislature is expected to grapple with when it returns in January.


Bonta said lawmakers will likely consider allowing existing medical dispensaries to be given temporary, interim power to sell marijuana for recreational use until the new licensing system is in place.

“We have to consider honoring the spirit of the law and making it work,” Bonta said. “If it’s legal to use but there is nowhere to buy, then I think we could consider a special, conditional, time-restrained license that could be operative for a short period of time while we bridge into the new regime that Proposition 64 envisions. That is definitely possible.”

Some in the industry would prefer to let cities and counties approve temporary licenses to sell recreational pot to avoid delays while people are allowed to possess marijuana.

“If you don’t fill that vacuum with regulated sales, then people are going to go to the black market,” Bradley said.


The Legislature will also have to decide whether to reconcile differences between Proposition 64’s regulation of recreational pot and the law approved last year by the Legislature for medical marijuana — or to have two different regulatory schemes.

The state is expected to create a task force to look at which rules to merge.

Some of the changes will be easy. The name of the state agency that will regulate and license marijuana sales will immediately change from the current Bureau of Medical Marijuana Regulation to the state Bureau of Marijuana Control to reflect its broader mission.

Lori Ajax, who was appointed to head the bureau last spring, is hiring staff and holding public meetings to draft regulations on issues that include licensing.


The approval of Proposition 64 also triggers a five-year, $15-million study by the California Highway Patrol to develop standards and protocols for determining when a marijuana user is too impaired to safely drive a vehicle.

The campaign this year had a big advantage over the failed effort of six years ago. With financial support from Parker and New York hedge fund billionaire George Soros, the campaign was able to raise about 10 times brought in by the opposition.

Newsom, the face of the campaign, argued that the national “war on drugs” has failed while disproportionately hurting minority residents and wasting law enforcement resources.

Proposition 64 was opposed by most major law enforcement groups, including the California Assn. of Highway Patrolmen, the Peace Officers Research Assn. of California, and the California Police Chiefs Assn.


Opponents, who also included California Sen. Dianne Feinstein, cited problems including teen drug abuse and impaired driving experienced in states where recreational use was previously legalized.

California Gov. Jerry Brown has voiced concerns in the past about marijuana use affecting worker productivity but did not take a position on Proposition 64, despite a request by five former heads of the U.S. Drug Enforcement Agency that that he oppose the measure.

It will continue to be illegal to smoke marijuana in public and at locations where tobacco use is outlawed, including restaurants and theaters. Violators will face fines.

Smoking pot is also prohibited within 1,000 feet of a school, daycare or youth center when children are present. In addition, motorists cannot smoke marijuana while driving.


The initiative bars the marketing of marijuana products to minors, which means ads would not be able to use symbols, language, music or cartoon characters aimed at appealing to those who are underage.

Federal law will continue to designate marijuana as an illegal drug, and federally regulated television and radio states are not allowed to advertise illegal drugs. If federal law should ever change, the ballot measure would require that broadcast, cable, radio, print and digital marketing only be displayed where at least 71.6% of the audience is reasonably expected to be 21 or older.

In addition to the excise tax, the ballot measure would charge a cultivation tax on growers of $9.25 per ounce for flowers and $2.75 per ounce for leaves. Cities and counties could also create their own excise taxes.

The state taxes are expected to generate up to $1 billion annually to be used to cover the state’s enforcement costs, allow research into impaired driving and pay for drug prevention, job placement, mental health treatment and drug abuse treatment.


Aaron Herzberg, an attorney and partner with marijuana product firm CalCann Holdings, said he expects California’s action to reverberate throughout the nation.

“Approving recreational marijuana in California, the sixth-largest economy in the world, and a state that often sets the trend nationwide, is the death knell of a failed policy of prohibition,” Herzberg said.

patrick.mcgreevy@latimes.com

Follow @mcgreevy99 on Twitter


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UPDATES:

11:45 p.m.: This story was updated with a response from Lt. Gov. Gavin Newsom.

This article was originally published at 8:50 p.m.