In the late 1930s, a film called “Reefer Madness” was released as a morality tale emphasizing the dangers of marijuana use. Since that era, and even when the film was used as a method of spoofing what advocates of legalization considered draconian laws and old-fashioned societal mores regarding pot, federal law has remained consistent in making it illegal, including for medical use. Even in Colorado and Washington where marijuana use is legal under state law, smoking it for any reason, medical or not, puts the user under a very slight risk of arrest and incarceration under federal statutes.

As marijuana laws have been liberalized and penalties reduced by local and state governments to a point where it’s no more of an issue than a speeding ticket, guidance from Barack Obama’s Justice Department gave local prosecutors the option to maintain a “hands-off” approach despite the fact that marijuana laws were unchanged at the federal level.

Thursday, however, Attorney General Jeff Sessions — who’s been known as a hardliner on drug laws — sent out a memorandum to all United States attorneys rescinding the Obama-era guidance. “Given the Department’s well-established general principles,” Sessions wrote, “previous nationwide guidance specific to marijuana enforcement is unnecessary and is rescinded, effective immediately.”

Proponents of legalization fret that this open season for prosecutors will kill the nascent marijuana industry in the crib. Reason’s Scott Shackford argues, “Whether or not a marijuana grower ends up in the crosshairs of a prosecutor depends on that prosecutor’s own goals and discretion, not a consistent, predictable application of law.” While this is true, we’ve known for some time that enforcement of law is not consistent or predictable in our hyper-political nation — not that it should be an excuse, but the genie appears to be pretty far out of the bottle now despite the belief by some that we are still a nation of laws.

This call by Sessions also rekindled the idea that maybe it’s time for Congress to act and allow states to have their say. “The Founders did not write the Constitution to impose uniformity on hemp,” notes Charles C.W. Cooke in National Review.

Cooke’s colleague Jim Geraghty concurs, convinced that Sessions is taking on “an unnecessary fight” with his memo. “We can argue whether the country would be a better or worse place with more marijuana users,” Geraghty continues. But the case of Colorado would seem to be a contention for returning to a more restrictive regimen, or at least slowing down the march toward state legalization. Currently, 29 states and the District of Columbia allow pot for at least medicinal use, with California the most recent to liberalize its laws.

Yet because we have no constitutional guidance on hemp (or any number of other things in which the federal government now asserts power), the state venue may be the proper place to have the argument. David French, also of National Review, makes a strong case for this by citing Colorado Senator Cory Gardner’s frustration with the Sessions memo. Gardner promises to hold up any Justice Department nominees until Sessions changes course and keeps a promise he made to the senator before his confirmation. Yet “Gardner is positioned exactly where he needs to be to reform America’s drug laws,” says French. “As a senator, he could introduce or co-sponsor legislation that explicitly decriminalizes marijuana at the federal level and leaves marijuana laws to the states. And there are multiple powerful arguments he could make in support of such a bill.” Instead, he’s blocking nominations — and he doesn’t even support legalization.

In reality, all Sessions did was shift policy to say that federal drug laws should be enforced, but it’s now largely up to the discretion of local U.S. attorneys. And the ones in Colorado announced they’ll make no effort to enforce the law.

In the end, it may be worth considering that “Reefer Madness” came out at a time when our nation’s moral compass still pointed more or less true north, but was allowing the expansion of the federal government at a rapid pace under FDR’s New Deal. We can’t agree that the compass is still pointing in the proper direction, but we can assert with confidence that this is an issue best left to the states, not the federal government — just as the Founders intended. Sessions is correct when he speaks of prosecutors managing the Justice Department’s “finite resources,” but he fails to advocate for how this issue can best be addressed.