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The Trump administration’s Department of Justice on Thursday rescinded a policy that discourages enforcement of federal marijuana laws – a move that sent shockwaves through California’s nascent marijuana industry.

In a memo sent to U.S. attorneys Thursday, Attorney General Jeff Sessions swept aside an advisory imposed by the Obama administration that silenced the marijuana enforcement efforts of the U.S. Department of Justice.

[related_articles location=”left” show_article_date=”false” article_type=”automatic-primary-section” curated_ids=””]In California, where passage of Proposition 64 is moving a shadowy $7 billion industry into a taxed and highly regulated structure, Lt. Gov. Gavin Newsom accused Sessions of “trampling on the will of California voters. … California will stand together to pursue all legal, legislative and political options to protect its reforms and its rights as a state,” as it has on climate, environmental and immigration issues.

But federal prosecution and conviction could be hard, according to Bay Area legal experts.

“For California, it’s not a game-changer,” said Robert J. MacCoun, a professor of Stanford Law School.

“But it sends two messages,” he added. “It sends a message to investors that this is a risky business and you ought to stay out of it. And it sends a message to the 42 states where it is not legal that ‘you might not want to take this on.’”

Sessions said prosecutors should use their own discretion, taking into consideration the department’s limited resources, the seriousness of the crime, and the deterrent effect that they could impose.

The announcement came the same day as the abrupt resignation of the U.S. Attorney for California’s Northern District. Brian Stretch, who had held the position since 2016, will step down Saturday, allowing the Trump Administration to name a new U.S. attorney — possibly one who shares Sessions’ hostility to cannabis. The Northern District covers coastal counties from Monterey north to the Oregon border, encompassing the nine-county greater Bay Area and two of the three counties in the cannabis-rich “Emerald Triangle.”

Calling it “the marijuana mess,” Sessions’ memo could create confusion in California, which has four U.S. attorneys in each district of the state, said Marsha Cohen, professor of law at UC Hastings College of the Law in San Francisco.

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“Will there be four different policies in California? Will Fresno be OK with marijuana, but you get arrested in San Francisco?” she said. “It seems totally unfair for criminal justice system to be unclear.”

“They have left a lot of this stuff alone for an extremely long time. It just wasn’t worth it,” Cohen said. She added: “All these prosecutors are already awfully busy. They have no shortage of cases.”

Californians voted to legalize medical marijuana in 1996 and recreational marijuana in 2016.

A historic law permitting sales of both products took effect on Jan. 1 — creating the largest legal pot market in the country. Hundreds of businesses have received temporary licenses from the state.

“The administration is conferring with the California Attorney General and other states in response to this action,” Lori Ajax, director of the state’s Bureau of Cannabis Control, said in a statement on Twitter. ” We expect the federal government to respect the rights of states and the votes of millions of people across America and if they won’t, Congress should act. Regardless, we’ll continue to move forward with the state’s regulatory processes covering both medicinal and adult-use cannabis consistent with the will of California’s voters, while defending our state’s laws to the fullest extent.”

U.S. Attorney General Jeff Sessions listens during a news conference July 13, 2017 at the Justice Department in Washington, DC. (Photo by Alex Wong/Getty Images)

The state long took comfort in the Obama era’s so-called Cole Memo, written in 2013 by Deputy Attorney General James M. Cole, which basically asserts that cannabis businesses need not worry about federal prosecution as long as they comply with state law.

The four-page memo granted federal attorneys a great degree of prosecutorial discretion as to how to use their crime-fighting resources, has been a critical document in the growth of the legal marijuana industry.

Thursday’s news sent tremors through the cannabis community. Businesses asked: Could SWAT teams bust marijuana dispensaries and shut down the state’s proliferating high-tech cultivators?

But Stanford’s MacCoun notes that Sessions hasn’t actually changed policy. Marijuana was a Schedule I drug before, and it’s a Schedule I drug now, he said. The Cole memo was simply an advisory memos to federal prosecutors, he said.

“Federal prosecutors who wanted to be aggressive could have done so before, and could do so now,”  MacCoun said.

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To decriminalize cannabis, Congress would have to instruct federal drug officials to re-schedule marijuana from a Schedule I to a Schedule II drug — essentially, moving it out of the ranks of drugs like heroin and regulating it more like oxycodone.

The president’s position is unclear, but he seems to favor allowing the medical use of marijuana, but not the recreational use. In February 2016, as a presidential candidate, Trump told Fox News: “By the way — medical marijuana, medical? I’m in favor of it a hundred percent.” At the 2016 Conservative Political Action Conference , Trump seemed critical of recreational marijuana in Colorado, saying “I think it’s bad. Medical marijuana is another thing, but I think it’s bad.”

But it takes more than a memo to win a conviction in court, especially if most people support its use, Cohen said.  “Juries might say: ‘Are you kidding?’ ”

Meanwhile, the industry has become woven into the commercial fabric of the state.  There are cannabis lobbyists in Sacramento and Silicon Valley’s venture capital firms have invested in the industry’s growth.

“It is a battle they could take on,” MacCoun said. “But it is not a battle that they could easily win — and it could be very costly.”

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