Michael Chernis is a Los Angeles-based attorney and expert specializing in the cannabis industry. The opinions expressed in this commentary are his own.

(CNN) Jeff Sessions announced Thursday that he is rescinding the Cole memo, which reflected the Department of Justice's relatively passive policy under the Obama administration since August 2013 on enforcement of federal cannabis laws.

If Sessions intended to quell the enthusiasm of California's cannabis business enthusiasts and government officials, he once again fell short.

Unlike announcements from the DOJ in past years threatening to ramp up federal enforcement of the cannabis laws, this announcement was met with little more than a yawn by cannabis businesses.

The harshest reaction came from local and state government officials -- in California and in other states -- who insisted that they were disappointed, concerned, and surprised by Sessions' move.

Now, unlike in prior years, government officials in California and elsewhere are totally aligned with cannabis businesses in resisting the federal government's threats.

In fact, the landscape has shifted so dramatically in recent years that some of the harshest critics of Sessions were senators and representatives, many of them prominent Republicans , from states with cannabis programs that generate much-needed medicine and tax revenue. They expressed outrage over this action by Sessions, claiming it belies promises he made to them before being confirmed by the Senate.

As a result, Sessions has alienated many in Congress, where he can ill afford to lose any friends. Given his recusal -- apparently against President Donald Trump's wishes -- from the Russia collusion investigation, he seems to be in a vulnerable spot with the President. Trump has said that he still stands with Sessions. But the attorney general still faces allegations from Democrats, who say that he perjured himself during last year's confirmation hearings.

Without protection from Republican allies in the Senate, Sessions' next appearance on Capitol Hill could be bloody. Cannabis might be the issue that undermines Sessions' already shaky support.

Apart from Sessions' announcement being unpopular, it really doesn't have any teeth. The medical and legal cannabis industry has grown so big that it would be impossible to make a dent in it -- let alone stamp it out through federal enforcement.

Moreover, Sessions did not actually announce that there would be a crackdown on cannabis businesses, but rather that it would be left to the discretion of the local US attorneys in the various districts to decide how and when to enforce the federal laws. This does not amount to much of a substantive change in policy, which begs the question of why Sessions bothered to make the announcement at all.

The Obama administration's policy essentially left it to the individual states to regulate its respective cannabis industries provided those businesses did not engage in activities that threatened federal priorities, like serving as a cover for other illegal activity or violence.

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Under the Cole memo, in the past four-plus years, the already robust medical cannabis industry continued to evolve with more than half the states now allowing some form of medical cannabis use and commercial activity, and now eight states including California, Colorado, Washington and Nevada permitting recreational or adult use of recreational cannabis.

Based on conversations I've had with federal prosecutors in Los Angeles, there does not appear to be much of an appetite on the part of federal prosecutors to go after cannabis. And if they do, at the moment their hands are tied, at least when it comes to medical cannabis. Since 2014, the federal budget has prohibited the DOJ from using federal funds to prosecute medical cannabis businesses pursuant to a budget rider championed by US Rep. Dana Rohrabacher of California, a Republican who considers Sessions a "longtime friend."

The Sessions' announcement was likely timed to create anxiety in California, only days after it began issuing permits for both medical and recreational cannabis businesses. California and its attorney general have been somewhat of a thorn in the side of the Trump administration, filing a number of lawsuits challenging various policies, and perhaps most significantly, allowing so-called "sanctuary cities" for undocumented immigrants.

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Although the spotlight seems to be on California, Colorado -- a swing state -- with a population that is dwarfed by California, has raked in hundreds of millions of dollars in tax revenue from its legalization of cannabis.

It would be wise for Sessions to remember that cannabis businesses exist in red and purple states, too. Its investors include prominent Trump supporters like Todd Mitchem . Any real enforcement efforts would alienate this administration's base and be a political risk.

For all of these reasons, there isn't much bark to Sessions' bite. And in fact, it could precipitate a legal battle with California and other states -- possibly overturning the authority of the federal government to even regulate legal cannabis businesses, an issue that has yet to be decided by the Supreme Court. That would be the ultimate irony to Sessions' move and an appropriate epitaph on his fight against cannabis.