Marijuana Moment is a wire service assembled by Tom Angell, a marijuana legalization activist and journalist covering marijuana reform nationwide. The views expressed by Angell or Marijuana Moment are neither endorsed by the Globe nor do they reflect the Globe’s views on any subject area.

US Senator Bernie Sanders is making a bold promise: If elected president, he will legalize marijuana in all 50 states on his first day in office.

“We will end the destructive war on drugs,” the 2020 Democratic candidate said at a rally days before this week’s Iowa caucus. “On my first day in office, through executive order, we will legalize marijuana in every state in this country.”

But while the pledge has been largely welcomed by reform advocates and cannabis enthusiasts, some experts question whether such immediate, sweeping action is legally or practically achievable.

The use of executive orders at the start of a presidency isn’t unprecedented — President Obama signed one aimed at shutting down the controversial Guantanamo Bay prison the day after he assumed office and President Trump issued an order scaling back Obamacare, for example — but there are unique challenges associated with a presidential move to unilaterally remove cannabis from the Controlled Substances Act.

To effectively end marijuana prohibition through the executive branch, according to an analysis from the Brookings Institution, the secretary of the Department of Health and Human Services or an outside party would have to file a petition, which would then be reviewed by the attorney general, who has usually delegated that responsibility to the Drug Enforcement Administration. The attorney general can also initiate the process on their own, requesting a scientific review directly to the health and human services agency. Under HHS, the Food and Drug Administration would then assess the scientific, medical, and public health implications before submitting that review to the Justice Department.

In other words, changing marijuana’s classification under federal law without an act of Congress is far more complicated than a single stroke of a presidential pen. While Sanders could theoretically make supporting descheduling a condition of nominating candidates to be HHS secretary or attorney general, it’s virtually certain he would not have those officials installed on day one of his presidency.

The new day-one, executive action proposal is a far more ambitious plan than the one Sanders previously floated. Last year, the senator said he’d take a systematic approach to legalization that would involve naming cabinet members who will “work to aggressively end the drug war and legalize marijuana” within 100 days of his taking office.

Bernie Sanders plan pledges immediate marijuana descheduling through executive action

But it appears the timetable has changed, with top aides reportedly including marijuana legalization in a list of possible executive orders — though Sanders has yet to formally sign off on them. Some experts are skeptical that this latest plan has legs, and some feel it reflects Sanders’ political desire to stand out as the most marijuana-friendly candidate, rather than an earnest attempt to expedite the descheduling process.

Here are some of the issues experts identified:

A president can’t change state marijuana laws

Federal descheduling wouldn’t directly repeal any state laws prohibiting marijuana, so the prospect of swift legalization across 50 states is questionable.

“The question first is, would states be compelled to do this? That is, does the president have the power to do this? That’s the first step,” John Hudak, deputy director for the Center for Effective Public Management at the Brookings Institution, told Marijuana Moment. “The second step actually raises a more important question, and that is: Can states continue to maintain a different schedule for a substance than a federal schedule? There’s plenty of evidence that a state could do that.”

While some state drug scheduling systems are tied to the federal system, it’s still the case that “the state has an opportunity to do something different, but it has to proactively do something different," he said.

“I think we typically don’t have situations in which the federal government is more lax and a state wants to be stricter on it, but it’s not out of the realm of possibility that that would be something federal courts would allow states to do,” Hudak said.

What’s more, even if state-level prohibitions did end as a result of descheduling, it would be without precedent for the federal government to dictate that they implement a regulated, commercial marijuana market. Instead, a situation could hypothetically emerge where cannabis would be legal, but there would be limited means of access, as is currently the case in Washington, D.C., where Congress has prohibited the district from using its local tax dollars to create a regulated system of sales.

“A president certainly cannot force that to be allowed in states by any kind of executive action,” he said. “It would really require an act of Congress to set up a commercial regulatory system nationwide, which, even then, you are on very shaky constitutional grounds to do that kind of thing.”

It’s also possible that Sanders could leverage federal funds to pressure states into adopting the policy change, requiring them to end cannabis prohibition as a condition of receiving certain dollars. That’s how Congress achieved setting a national drinking age minimum of 21, for example, by threatening to withhold 10 percent of federal highway construction funds if states didn’t comply.

An executive order can’t get around regulatory requirements

“There are procedures that have to be followed to remove it,” said Sam Kamin, a law professor at the University of Denver. “It might not take months or years, but it certainly won’t be the first afternoon of the Sanders presidency.”

Hudak agreed: “An executive order is not a means by which a president can do this. Presidents need to draw on statutory authority or constitutional authority in order to use an executive order to make some sort of policy change. The president is explicitly restricted by the Controlled Substances Act from doing this through a non-regulatory process, and the Supreme Court has ruled repeatedly that Congress’s policy choices in the CSA are constitutional and within their power. It does not grant constitutional authority to the president in any of those rulings. No, President Sanders or President Anyone cannot do this by executive order.”

International drug treaties could complicate things

And then there’s the question of international law. Opponents of ending prohibition often point to global drug treaties to which the United States is a party that technically require member nations to keep marijuana illegal.

A Sanders administration could hypothetically withdraw the United States from the treaties, as past presidents have done to advance policies that run counter to international agreements. President Bush withdrew from the Anti-Ballistic Missiles Treaty in 2001, for example, and while it was challenged in a lawsuit, a federal district court dismissed the case, setting a precedent.

A 2016 legal brief from the Congressional Research Service discussed the ambiguity of withdrawal procedures for Senate-approved treaties like the Single Convention on drugs. While the Senate is empowered to “advise and consent” in the drafting of treaties, the statute is “silent with respect the power to withdraw from them.” There have been past instances where “the President has unilaterally terminated treaties without any form of legislative approval,” but in other cases, Congress has either given advance authorization or approved a withdrawal after the fact.

All that said, there’s a more simple workaround to the treaty problem: Sanders could just ignore it altogether, as Canada and Uruguay have when they legalized marijuana nationwide. Because treaty obligations are sometimes flouted by the United States and other countries when they’re inconvenient and because they often lack enforcement capabilities, experts broadly dismissed the notion that a Sanders presidency would be inhibited by international bodies like the United Nations.

“If the UN is not going to punish Uruguay, I don’t think they’re going to punish the United States,” Hudak said.

Sanders’ campaign won’t explain its plan

It’s possible that Sanders’ team could take some proactive steps to work around all of these statutory rules, including the treaty obligations.

For example, it could work with incoming personnel for the Justice Department’s Office of Legal Counsel during the transition between the election and inauguration day to draft a memo stipulating that the executive order can stand, so when it’s issued on day one, the administration could point to that document and justify the action. However, it’s still possible that a court could later challenge the legal reasoning.

Marijuana Moment reached out several times to Sanders aides for specifics on exactly how the candidate plans to “legalize marijuana in every state in this country” via executive order on his first day in office, but they did not respond by the time of publication.

Warren Gunnels, a senior adviser on the senator’s campaign, wrote in a Twitter post Sunday that not only would cannabis be legalized on day one, but the executive order would be signed at 4:20 p.m., referencing the unofficial marijuana holiday 4/20 that is rumored to have been inspired by a group of high school students who met at that designated time to smoke in the early 1970s.

Take a look at the origins of ‘420’ on the unofficial marijuana holiday

Even if unfeasible, Sanders’ pledge has political value for reformers

Despite these obstacles, some legalization advocates view Sanders’ promise as a politically important — if symbolic — proposal.

“There are open questions about if and how a president could technically deschedule, as opposed to reschedule, marijuana on Day 1 via a simple executive order,” said Erik Altieri, executive director of NORML. “There is and will be much debate about the technicalities, but what is truly important about this recent pledge is that for the first time in political history we have a front-runner for a major party nomination treating marijuana policy as a top-tier issue.”

“Executive order or not, if we had a president who elevated marijuana policy and backed it using the bully pulpit in this way, it would undoubtedly apply even further pressure for Congress to take action on important pending legislation such as the MORE Act,” he said, referring to a bill to deschedule cannabis and promote social equity that was approved by the House Judiciary Committee last year.

Others aren’t so bullish on Sanders’ decision to pitch an expedited legalization agenda, arguing that it’s practically ambitious at best and politically dangerous at worst.

“I think frankly it’s political pandering,” said Hudak, of the Brookings Institution. “The Sanders [original 100-day plan] is a very effective administrative strategy to make sure that all the i’s are dotted and t’s are crossed. To step away from that and effectively do a liberal version of President Trump’s behavior — and that is, ‘let me do this via executive order and be damned what the Constitution or statute say’ — is not something a lot of Democrats really have an appetite for right now.”

“I think, what’s worse, even if in a scenario where this were somehow upheld by an increasingly conservative federal judiciary, what is then-President Sanders doing? He’s setting up a system in which four or eight years later, a Republican president can come in and undo with the stroke of a pen,” he said. “I don’t think any cannabis reformer wants cannabis policy to be set in a way that drastically can change from presidency to presidency.”

Kamin, the law professor in Denver, said that Sanders’ proposal “is not one that comports with the separation of powers and federalism.”

“Whether you call that symbolic or whether you call that metaphorical or whether you call that puffery, what Sanders is signaling is, ‘I want to be the federal legalization candidate.’ The race was once crowded with senators who had legalization plans. [Sen. Elizabeth Warren (D-MA)] is probably the principle person left in the race who has proposed legalization at the federal level. What I see there is Senator Sanders trying to claim that issue for himself.”

Steve Fox, president of VS Strategies, the public affairs consulting arm of the Vicente Sederberg LLP law firm, said even if Sanders successfully moved to reclassify marijuana under federal law, it wouldn’t mean that the penalties against it would be automatically erased from the law books.

“I think rescheduling would be possible, given that a DEA administrative law judge recommended rescheduling in 1988 and that recommendation was never followed. But marijuana’s penalties under federal law are not connected to its scheduling,” Fox said. “The law provides specific penalties based on the amount of marijuana one possesses. As far as I understand, an executive order cannot be used to simply eliminate crimes from the U.S. Code that a president doesn’t like.”

Douglas Berman, a professor at Ohio State University’s Moritz College of Law and author of the Sentencing Law and Policy blog, falls somewhere in the middle on the question of Sanders’ ability to actually achieve unilateral descheduling versus the political implications of simply pledging to do so.