By Bob Egelko and Peter Fimritec

San Francisco Chronicle

SAN FRANCISCO — It’s far from clear whether U.S. Attorney General Jeff Sessions’ announcement will have much of an impact on the nation’s steadily expanding marijuana industry or its millions of users.

Since 2014, Congress has attached amendments to the Justice Department budget forbidding interference with laws in states that allow medical marijuana, a list that began with California in 1996 and has grown to 29 states and the District of Columbia, with a combined 60 percent of the U.S. population. A federal appeals court has ruled that the amendments prohibit prosecution or other government legal action against medical marijuana suppliers who follow state laws.

Congressional supporters want to expand that protection to cover nonmedical sale and use of marijuana by adults, now legal in eight states, including California, along with Washington, D.C. They plan to add that proposal to a spending bill that is needed by Jan. 19 to keep the government operating, and said Sessions may have unintentionally helped their cause.

“The (Sessions) memo will mobilize us, mobilize the people around the country’’ who support legalization, Rep. Dana Rohrabacher, a Republican from Orange County who has sponsored the budget amendments, said in a conference call by the House Cannabis Caucus. He said the federal government must “respect all of the decisions of the states when it comes to cannabis.”

Another caucus member, Rep. Earl Blumenauer, a Portland Democrat, said, “This is outrageous. Going against the majority of Americans — including a majority of Republican voters — who want the federal government to stay out of the way is perhaps one of the stupidest decisions the Attorney General has made.”

Rohrabacher wasn’t the only Republican taking on Sessions. Sen. Lisa Murkowski of Alaska said Sessions’ announcement was “disruptive to state regulatory regimes.” Sen. Cory Gardner of Colorado, which like Alaska and California has legalized adult recreational use of marijuana, said he was prepared to hold up the confirmation of Justice Department nominees if Sessions pursued his policy.

Colorado’s U.S. attorney, Bob Troyer, who was appointed to his office by Sessions in November, said Thursday the attorney general’s directive would not change his policy to prosecute only marijuana operations that “create the greatest safety threats to our communities.”

‘Congress should act’

Lori Ajax, chief of California’s Bureau of Cannabis Control, which oversees the state’s regulation of the marijuana industry, said California was conferring with other states to respond to Sessions’ action.

“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,” she said.

Sessions is a longtime crusader against marijuana, a drug he has likened to heroin. In his memo to prosecutors, he said they should file charges in marijuana cases based on “the seriousness of the crime, the deterrent effect of criminal prosecution, and the cumulative impact of particular crimes in the community” — appearing to leave the door open to charging individual users as well as suppliers.

President Trump, who in other contexts has advocated “states’ rights,” provided a degree of support for his attorney general through spokeswoman Sarah Huckabee Sanders.

“The president believes in enforcing federal law,” Sanders said at Thursday’s press briefing. She said Sessions’ directive “simply gives prosecutors the tools to take on large-scale distributors and enforce federal law.” She did not elaborate.

The memo that Sessions withdrew, issued in 2013 by James Cole, a deputy attorney general in President Barack Obama’s Justice Department, advised federal prosecutors to let states enforce their own marijuana laws.

Marijuana advocates said the Obama administration policy hadn’t had a long-lasting effect on use or regulation of the drug, and the Trump administration probably won’t either.

“Marijuana has been under a prohibition regime entirely in the time that the industry has expanded to where it is today,” said Aaron Smith, executive director of the National Cannabis Industry Association, representing more than 1,500 marijuana-related businesses. “The biggest growth phase was during the (George W.) Bush administration, when we were facing SWAT team raids, and prosecutions on a nearly weekly basis in California.”

Arcview Group, an Oakland investment and market research firm that studies the cannabis industry, forecast an $11 billion U.S. market for legal marijuana this year — just over 60 percent for medical use, the rest for recreational use — and said it would continue to expand.