Attorney General Jeff Sessions. (Jay LaPrete/AP)

What will happen to legal marijuana under President Trump?

That's been a vexing question for cannabis advocates ever since Trump named criminal justice hard-liner Jeff Sessions (of “Good People Don't Smoke Marijuana” fame) as attorney general. Although Sessions's beliefs about marijuana legalization are well-known (he hates it), the separate question of what he intends to do about it has so far remained a mystery. But a letter from the attorney general to officials in Washington state, obtained this week by the HuffPost, sheds considerable light on the question.

It suggests that while Sessions remains deeply skeptical of efforts to legalize recreational marijuana use, the Justice Department's actions on the issue are, for now, still dictated by the Cole Memo, an Obama-era document that lays out a policy of federal non-interference with state laws so long as public health and public safety are not threatened.

But the letter also includes a laundry list of public health and safety concerns compiled by federal authorities, potentially laying the groundwork for more aggressive federal interventions in Washington and elsewhere in coming years.

“A letter like this is a pretty important indicator” of Justice's current thinking on marijuana issues, said John Hudak, a drug policy expert with the Brookings Institution. “It tells us that the attorney general is serious about enforcing marijuana law under the Cole Memo.”

Last week the attorney general received recommendations from a hand-picked task force on how the federal government should approach marijuana legalization issues. But so far those recommendations haven't been released publicly, prompting criticism from advocates and members of Congress.

Sessions's letter, dated July 24, reiterates that “Congress has determined that marijuana is a dangerous drug and that the illegal distribution and sale of marijuana is a crime,” and that “the Department remains committed to enforcing the Controlled Substances Act in a manner that efficiently applies our resources to address the most significant threats to public health and safety.”

While on the surface those sentences read like an aggressive statement of federal prerogative on marijuana enforcement issues, they come nearly word-for-word from the 2013 Cole Memo, which set a policy of federal non-interference, so long as a number of public health priorities, like preventing teen use and diversion to other states, were met.

While the Cole Memo reserved the right of federal authorities to investigate and prosecute state-legal marijuana operations at any time, federal attorneys by and large refrained from doing so, with a few notable exceptions.

Sessions's letter acknowledges correspondence from Washington and other legal marijuana states, which characterize the Cole Memo as “indispensable” to those states' marijuana regulatory structures. Sessions then goes on to underscore the final sentence of the Cole Memo: “Nothing herein precludes investigation or prosecution, even in the absence of any one of the factors listed above, in particular circumstances where investigation and prosecution otherwise serves an important federal interest.”

Sessions then cites a litany of concerns about the outcomes of Washington's regulatory experiment, culled from a report by the Northwest High Intensity Drug Trafficking Area (HIDTA), a federally funded drug task force. Those concerns include diversion of legal marijuana from Washington to other states, an increase in drivers testing positive for past marijuana use, and an increase in marijuana-related calls to the state's poison control center.

“This report raises serious questions about the efficacy of marijuana 'regulatory structures' in your state,” Sessions concludes.

Legalization opponents were pleased with the letter. "Public health and road safety are suffering," said Kevin Sabet of the group Smart Approaches to Marijuana. "This letter suggests that the Feds are serious about getting a full accounting of what is actually happening in states with legal marijuana."

But Hudak has own concerns about the accuracy of data Sessions is relying on. Those reports are compiled solely by law enforcement authorities and are “notorious for cherry-picking data and failing to put data into context,” Hudak said. He points out that while the report was issued in 2016 it includes only data covering the first six months of Washington's commercial market, which opened midway through 2014.

“We don't know, based on [the HIDTA] data, what Washington has done since then,” Hudak said. “The attorney general is drawing these grand conclusions based on incomplete data or data taken out of context.”

Governors in Oregon and Colorado have submitted their own reports to the attorney general, offering generally positive assessments of the marijuana markets there: State and federal data sources show youth drug use is down, for instance. The legal market is generating thousands of jobs and billions in economic activity. Arrests are down and traffic fatalities are flat.

These effects are just as important to consider as the potentially negative ones, Hudak says. But so far Sessions has given little indication that he's interested in a full portrayal of the data.

“The attorney general has an agenda when it comes to marijuana,” Hudak said, “and he is looking at what is going on in Washington with clear blinders on that allow him to see only what he wants to see, not necessarily what the reality is on the ground.”