A woman holds up a copy of the U.S. Constitution she brought to a House Judiciary Committee hearing in Washington, D.C. (Chip Somodevilla, Getty Images)

What is the Supremacy Clause and what does it mean for states’ rights to legalize marijuana?

When it comes to laying down the law on marijuana, it’s a convoluted dispute.

Amid the renewed attention on state legalization by new Department of Justice leader Jeff Sessions, here’s a refresher.

Marijuana in the age of Trump: A Cannabist special report

Part 1 | ‘Something’s going to have to give’: An untenable conflict between feds, states

Part 2 | Federal marijuana law enforcement: What you need to know

The idea of federal preemption of state law is based on the U.S. Constitution’s Supremacy Clause (Article VI, Clause 2), which states that the Constitution “shall be the supreme law of the land.”

The Supremacy Clause’s relations to state-enacted marijuana laws has been addressed in a handful of legal articles, including a UCLA Law Review report from 2015:

“The constitutional question that will determine the outcome of any preemption lawsuit seeking to invalidate state marijuana laws is whether state laws allowing the sale, cultivation, and use of limited amounts of marijuana creates an impermissible “conflict” — as that term has been defined by the Supreme Court — with the (Controlled Substance Act) provisions prohibiting marijuana altogether.”

However, there exists a “significant constitutional counterweight” in the Tenth Amendment’s anti-commandeering doctrine, the authors note and reference a 2009 paper by Vanderbilt Law School professor Robert Mikos titled, “On the Limits of Supremacy: Medical Marijuana and the States’ Overlooked Power to Legalize Federal Crime.”

The anti-commandeering principle constrains the preemption power of the government, wrote Mikos, an expert on federalism and drug law.

“That rule stipulates that Congress may not command state legislatures to enact laws nor order state officials to administer them. To be sure, the rule does not limit Congress’s substantive powers but rather only the means by which Congress may pursue them. For example, Congress may designate the sites for new radioactive waste dumps, though it may not order state legislatures to do so; and it may require background checks for gun purchases, though it may not order state law enforcement officials to conduct them. All the same, the anti-commandeering rule constrains Congress’ power to preempt state law in at least one increasingly important circumstance — namely, when state law simply permits private conduct to occur — because preemption of such a law would be tantamount to commandeering.”

A preemption would be unprecedented and, very likely, unsuccessful, Mikos said in an interview with The Cannabist.

“Sessions might prefer that Colorado roll back the clock and go back to 2011, but he can’t do that,” he said.

While the Supremacy Clause has been cited previously in marijuana-related cases — including a January Colorado Supreme Court decision on the asset forfeiture of marijuana and the 2015 Coats vs. Dish Network lawful termination case — there’s not yet been legal precedent involving the relationship between federal preemption and state marijuana laws, drug policy and law experts say.

The Supremacy Clause is referenced in an ongoing consolidated federal appeals court case against Colorado marijuana laws.

“The federal law is crystal clear,” Campbell University law professor Zachary Bolitho said, noting that if state law conflicts with and interferes with the overall goal of the federal government, “the state law should give way.”

When Nebraska and Oklahoma sued Colorado in late 2014, the case they presented to the U.S. Supreme Court alleged that an outflow of marijuana from the 420-friendly state created a burden for their law enforcement agencies.

At the time, Bolitho likened the case to legal actions taken in Arizona in 2012. Former U.S. Attorney General Eric Holder successfully argued in Arizona vs. the United States that federal law preempted the southwestern state’s immigration law. In an op-ed in the Los Angeles Times, Bolitho wrote that the same rule should apply in
the states’ marijuana dispute.

The U.S. Supreme Court declined to hear Nebraska and Oklahoma’s case and the two states subsequently intervened to join the consolidated preemption/racketeering case that’s pending a final decision by the 10th U.S. Circuit Court of Appeals.

Erasing regulation

If the federal government were to win on the grounds of preemption, Mikos argues that it could create a situation where a state would be stripped of its marijuana regulations but not the law allowing for the sale, possession, cultivation and distribution.

“That’s shooting themselves in the foot,” he said. “That’s not going to clamp down on the industry, that’s just going to free this marijuana industry of all those hassles of state law.”

It would be a “legal free-for-all,” said Sam Kamin, who also served as an author of the UCLA Law Review article. Kamin is the Vicente Sederberg professor of marijuana law and policy at the University of Denver’s Sturm College of Law.

Kamin said: “You’d end up in a far worse situation if you win that lawsuit than if you lose it. … That sort of lawlessness is exactly what Colorado and the federal government don’t want.”

But other federal actions — be it legal maneuvers or a series of selective raids — could have unintended consequences, said Mark Bolton, the state of Colorado’s acting marijuana adviser.

“My concern would be it’s going to drive producers underground; it’s going to drive consumers to the black market,” he said. “With that, you’re going to see a new wave of dangerous activity.”