If there’s one consistent theme of U.S. Attorney General Jeff Sessions’ nearly 40 years in public life, it’s that he has been an opponent of marijuana, be it in a law enforcement capacity or a policymaking one.

Last week, the Sessions Justice Department announced it was ending the Obama-era policy that directed prosecutors not to interfere with state governments allowing legalization of the drug, which is in direct conflict with federal statutes. That gave prosecutors the go-ahead to enforce federal drug law in the seven states like Colorado and Washington, where it has been legalized for recreational use and in the 27 states where it is legal for medicinal use.

“It is the mission of the Department of Justice to enforce the laws of the United States, and the previous issuance of guidance undermines the rule of law and the ability of our local, state, tribal and federal law enforcement partners to carry out this mission,” Sessions said in a strongly worded statement. “Therefore, today’s memo on federal marijuana enforcement simply directs all U.S. Attorneys to use previously established prosecutorial principles that provide them all the necessary tools to disrupt criminal organizations, tackle the growing drug crisis and thwart violent crime across our country.”

The memo drew a swift rebuke from members of Congress, including Rep. Matt Gaetz, who represents the adjacent First Congressional District of Florida.

“Today, Attorney General Jeff Sessions announced that the Justice Department would no longer follow the guidance of the Cole Memorandum — a long-established, common-sense guideline instructing the federal government to crack down on dangerous drug crimes, rather than harmless medical marijuana patients. This disappointing and cruel decision is a huge step backward for states’ rights, for common-sense reform and for the American people.”

It is indeed a head-scratcher. With all that’s going on regarding the Trump Justice Department — the Russia investigation, Hillary Clinton, the crackdown on illegal immigration, the opioid crisis — why has Sessions decided to make this an issue, especially given it’s a hot-button issue for so many Americans?

Sessions’ attitude toward pot first hit the national radar in 1986 when he was a nominee for the federal bench under President Ronald Reagan. In his prosecution of the Ku Klux Klan in the early 1980s, Sessions quipped it was difficult to nail down what the Klan had done one night because they had their memories impaired from marijuana use and that he used to support the Klan until he learned they smoked pot.

Sessions explained he was joking, but his opponents used it as, “That time Jeff Sessions spoke favorably about the KKK.” Obviously, that moment in his history was ill advised, but early on he had revealed his position on marijuana.

Initially, Sessions’ appointment to the AG post caused panic in the pro-legalization movement. Erik Altieri, executive director of the National Organization for the Reform of Marijuana Laws (NORML), railed against Sessions immediately upon his nomination.

“Jeff Sessions is certainly one of the more militant prohibitionists in Congress,” Altieri said in an interview with Denver-based Westword magazine in December 2016. “He’s an extremely conservative member of Congress, and he’s made numerous statements on this topic, none of which bode very well about how he’d handle state marijuana policy if he had his druthers.”

Sessions obviously didn’t disappoint with his memorandum last week. Here’s the problem: Sessions is in the right. Article VI, Clause 2, also known as the Supremacy Clause, established that federal law takes precedence over any state laws, referendum or constitution.

Conservatives in Alabama took it on the chin with defeats over battles on same-sex marriage (ask Roy Moore) and immigration (H.B. 56). The same standard applies to marijuana, even if it seems like a bizarre fixation for the embattled Trump Department of Justice.

The obvious correct response is to change the federal law if you want to legalize marijuana. Well, as we’ve learned over the past two decades, an act of Congress is hard to come by, and marijuana legalization just doesn’t appear to be feasible in this era of gridlock in Washington.

Let’s say Sessions’ Justice Department follows through with efforts to shut down the legal marijuana trade in America and abide by federal law. Imagine an Alabama casino-style law enforcement raid in the dark of night captured by the TV cameras.

Oh, the outcry. Overnight, the industry that has an estimated $5 billion in sales annually, and growing, was shut down by the Feds. Jobs are lost. People are angry.

That’s how you force Congress to act — create the crisis. Otherwise, it remains a backburner issue that is only trotted out as a desperate get-out-the-vote measure. If left to their own devices, Congress might consider it, but there would be a carve-out for every special interest under the sun.

The consensus among most Americans seems to be to let the states decide if they want to make marijuana legal and whether it should be legal for medicinal or recreational use.

Make this issue about states’ rights, not legalizing potentially harmful narcotics, and it becomes much more difficult for conservatives such as Jeff Sessions to oppose.