Drug Policy

Congress Should Not Legalize Marijuana, Marco Rubio Says, Because Black-Market Weed Is 'Laced With Fentanyl'

The Florida senator has a long history of defending prohibition, but it has not improved his arguments.


When Sen. Marco Rubio (R–Fla.) was seeking the 2016 Republican presidential nomination, a local paper noted that he had "a long history speaking out against marijuana legalization." Given that history and the fact that Rubio's position is rejected by two-thirds of Americans, you might think he would be prepared to defend marijuana prohibition with cogent arguments.

If so, you would be wrong. In a recent interview with a Pensacola TV station, Rubio worried that legalization would encourage teenagers to use cannabis, which would be a "gateway" to other drugs, and warned that black-market marijuana is "laced with fentanyl." All three arguments are logically and empirically dubious. If this is the best that Rubio can do, he'd be better off changing the subject.

"When you decriminalize something, the message that you're basically sending people is it must not be that bad," Rubio said. "Now, suddenly, you're an 18- or 17-year-old, [and you] say, 'Well, I know marijuana, you tell me not to smoke it, but you know what? It can't be that bad, because the federal government made it legal.' And so all of a sudden now, you're going to have a problem in this country, because that becomes a gateway. We know that marijuana use is often the first thing that people use before they move on to something else. We've also seen, by the way, marijuana being purchased off the streets that's laced with fentanyl and other drugs, and it's killing people."

We obviously don't know yet what impact repealing the federal ban on marijuana would have on the impressionable teenagers that Rubio imagines. But there is little evidence that legalizing marijuana for medical or recreational use at the state level, as 37 states already have done, has boosted underage consumption.

A 2013 study published in the American Journal of Public Health found that medical marijuana laws "have not measurably affected adolescent marijuana use in the first few years after their enactment." A 2014 study published in the Journal of Adolescent Health likewise "did not find increases in adolescent marijuana use related to legalization of medical marijuana." Similar results have been reported in The Lancet Psychiatry (2015), Drug and Alcohol Dependence (2017), Addiction (2018), and The American Journal of Drug and Alcohol Abuse (2019).

The research on recreational legalization is a bit more mixed, but the weight of the evidence does not support Rubio's concern. A 2017 JAMA Pediatrics study found that cannabis consumption by eighth- and 10th-graders rose slightly in Washington state after recreational use was legalized but stayed the same in Colorado. A 2018 study reported in Substance Abuse: Research and Treatment found "no significant differences" in adolescent substance use before and after recreational legalization in Washington, although "there were significant post-policy increases in problems and use disorder symptoms." A 2019 Prevention Science study "did not find a significant effect associated with the introduction of legal sales of recreational marijuana to adults in Colorado on adolescent (illegal) use."

A 2018 APA PsycNet study found evidence that legalization of recreational marijuana in Oregon "did not increase marijuana use for youth who did not use marijuana but did increase use in youth who were already using." A 2019 study reported in JAMA Pediatrics, based on data from the Youth Risk Behavior Survey (YRBS), found "there was no evidence that the legalization of medical marijuana encourages marijuana use among youth" and said "marijuana use among youth may actually decline after legalization for recreational purposes."

A 2019 systematic review and meta-analysis in BMJ Open found the studies suggested "a small increase in cannabis use among adolescents and young adults following legalisation of cannabis for recreational purposes." But it noted that "studies characterised by a very low/low risk of bias showed no evidence of changes in cannabis use following policy modifications."

According to a 2021 analysis published in the Journal of Adolescent Health, YRBS data "suggest minimal short-term effects of [recreational legalization] on adolescent substance use, with small declines in marijuana use and increase in the likelihood of any e-cigarette use." Yet another study based on YRBS data, reported in JAMA Network Open last year, found "there were no significant associations between enactment of [recreational or medical legalization] and marijuana use among high school students."

What about Rubio's fear that marijuana is a "gateway" to more dangerous drugs? Rubio probably knows from personal experience that the vast majority of people who smoke pot don't become heroin addicts. Taking a page from George W. Bush, Rubio has refused to say whether he smoked pot in his youth, based on a rationale that implicitly concedes he did: "If I tell you that I did, then kids will look up to me and say, 'Well, I can smoke marijuana, because look how he made it.'"

That's a dangerous message, Rubio thinks, because those kids, unlike him, might find that pot is the first step on the road to ruin. But while the "gateway drug" trope has been popular among pot prohibitionists since the 1950s, the issue is much more complicated than Rubio suggests.

It is true that marijuana "is often the first thing that people use before they move on to something else." It is also true that people who try marijuana are more likely to try other drugs than people who never try marijuana. But that does not mean marijuana use causes people to "move on to something else." Many studies have tried to distinguish between correlation and causation by controlling or adjusting for confounding variables, with mixed and contentious results.

The psychologist Andrew Morral and his colleagues at the RAND Drug Policy Research Center have shown that an underlying propensity to use drugs, combined with the relative availability of different intoxicants, could entirely account for the three phenomena emphasized by advocates of the gateway theory: 1) that people tend to use marijuana before other illegal drugs, 2) that people who use marijuana are more likely to use other illegal drugs, and 3) that the likelihood of progression increases with the frequency of marijuana use. Their mathematical model did not disprove the gateway theory, but it did prove that the gateway theory is not necessary to explain these observations. Morral et al. concluded that "available evidence does not favor the marijuana gateway effect over the alternative hypothesis that marijuana and hard drug initiation are correlated because both are influenced by individuals' heterogenous liabilities to try drugs."

I suspect that Rubio is about as familiar with research on the gateway theory as he is with research on how legalization affects adolescent marijuana use. But his third argument against legalization, which hinges on the hazards of marijuana "laced with fentanyl and other drugs," can be debunked without delving into the scientific literature, because it plainly makes no sense.

It is worth noting that fentanyl-laced marijuana may be nothing more than "an urban legend," as an intelligence officer with the New England High Intensity Drug Trafficking Area put it. But even if it were a real and significant threat, it would be entirely a product of the black market created by prohibition. Legalization—the very policy that Rubio ostensibly is arguing against—is the most effective way to assure cannabis consumers that their pot is not mixed with something they neither expect nor want. Rubio's obliviousness to that point speaks volumes about the logically and scientifically bankrupt foundation of the policy he thinks he is defending.

NEXT: Gatekeepers Very Afraid That Elon Musk Will Remove the Gates From Twitter

Editor's Note: We invite comments and request that they be civil and on-topic. We do not moderate or assume any responsibility for comments, which are owned by the readers who post them. Comments do not represent the views of Reason.com or Reason Foundation. We reserve the right to delete any comment for any reason at any time. Report abuses.

  1. Sounds like the CDC after they found that black-market vapes were causing injuries to vapers. Their response was to ban nearly all legal products and drive vapers to the black market.

    1. Marijuana has potential as a gateway drug when it is illegal. Here's how: you're at your dealer's house picking up some cannabis and Oh, what do you know, there's another guy there, and he's a dealer, too. He sells cocaine. You're pretty high already after smoking down your pot dealer, would you like to try some coke?

      This, of course, does not happen in a dispensary.

      1. I can tell you from experience that this is exactly how it works. When you have to get your pot from shady people, yin’s easy to get sucked into all their other shady shit.

      2. Duh hay Der Marco, if da stuff is leegal. It won’t bee blak merket no mute.

  2. In his defense, Marco Rubio is a putz.

    1. You misspelled idiot.

      1. He's almost as stupid on his topic as Liz Warren and AOC are on economics.


        1. You mean Rubio is advocating policies that work well in nearly every other wealthy democracy besides the US?

          That's a funny definition of stupid.

          1. Wow. What wealthy democracy are you referring to? Canada? Australia? *wink*

        2. Of just about anything else. Really, just about any and everything else with the remotely possible exception of breathing. And that's merely because neither one of them actually has to think in order to do so.

          It's a good thing they're in charge, of something?

  3. Remember that time Rubio gave the Republican response to Obama’s SOTU and he had wicked cottonmouth?

  4. A 2013 study published in the American Journal of Public Health found that medical marijuana laws "have not measurably affected adolescent marijuana use in the first few years after their enactment."

    Just so you know, it's 2022, so be careful when you're citing 10 yr old studies on the impact of a rule or law that has had ten years hence to percolate.

    None of this is to say that Rubio's arguments are cogent, or if they even matter.

    Alcohol is probably (or could be) a gateway to many other things, yet it's not illegal. So I wouldn't worry too much if legal weed led to a slight increase in teenage consumption (which I have very little doubt that it probably did).

    1. California legalized medical marijuana in 1996. 17 years before the study. 8 more states followed in time to have 10 years or more before the study. As the other links cited suggested, the subsequent 9 years haven't changed the outcome.

      Why on earth do you think more will?

  5. Question for the group... is Marco Rubio a wise Latino?

  6. Marco Rubio officially qualifies as a RINO...

    1. Because he is dissenting from the longstanding Republican pro-drug platform?

      1. No. It’s because he sometimes goes along with evil things that you democrats want. Like open borders.

        1. You have not demonstrated why it's evil to let people walk from one place to another.

          1. I know, I know… You’re a criminal, so property lines aren’t a concept to you either, huh?

            1. Still no response… huh. Lemme wrap this up then:

              Tony: “Whose property is the public beach north of the Rio Grande?”

              Me: “I don’t know, but after a bunch of illegals enter and have their way with it, I doubt that anyone would want it to be their property.”

              Tony: “You still havent demonstrated what it is about walking from one place to another that makes one an illegal”.

              Me: “thats becuz youre a criminal. We’re spinning in circles now. As always. I can do that on my own.”

              1. I've seen Trumper lawns. Not exactly the gardens of Versailles, are they?

            2. The border of a nation is not the same as the property line of someone's private property. The nation itself is no one's private property.

        2. I’m always wondering wtf people think body autonomy is

    2. He’s much better when he’s talking about abolishing the semiannual clock change - an idea so retarded that even Rubio can see how dumb it is.

  7. Scary drugs are scary!

  8. Sounds like giving the vote to 18 year olds was a mistake. It just signaled that politics was A-OK, since the government made it legal. We need to undo this. Make voting illegal, so only outlaws will vote!

  9. As usual, the control freaks (of both sides!) point to bad things that happen during prohibition to argue that prohibition can't be ended.

  10. I don't believe the whole "fentanyl-laced marijuana" thing. Why would weed dealers risk killing off their junkies? And If the logic is that weed is more addictive when it's laced with fentanyl, how much difference does that really make? If it's weed, stoners are going to buy it and keep buying it.

    And wouldn't dealers be making less money by selling weed laced with fentanyl, rather than selling the weed and fentanyl separately?

    1. Every single one of your points is absolutely correct.

    2. I suspect if it is actually laced with fentanyl, a lot of stoners would find another source that isn't. And a few would become fentanyl addicts and give up on the weed. The effects of the two drugs is rather different and there are reasons why weed is a much more popular drug. Most stoners aren't mindless junkies who will smoke whatever they can get their hands on any more than people who have a few drinks every night are. Especially now that the weed market is so open and diverse and people seek out not just weed, but particular varieties and forms.

      1. Marijuana is a gateway drug to fentanyl like vodka is a gateway drug to Listerine.

    3. Pot smokers usually aren’t ‘junkies’.

    4. "And wouldn't dealers be making less money by selling weed laced with fentanyl, rather than selling the weed and fentanyl separately?"

      Top grade marijuana can be extremely expensive and fentanyl is comparatively cheap. Lacing low grade marijuana with fentanyl is not completely implausible for unscrupulous dealers. Mutton dressed as lamb.

    5. I smoked a fuckton of pot between the ages of 18 and 25 (early 2000s-ish). I also hung out with tons of people who smoked pot all the time and bought weed from dozens (maybe hundreds) of different sources.

      In all that time, I only knew one guy who one time who smoked boat (pot laced with PCP) that he thought was just weed. And he didn’t buy it; he was smoking it with someone else. And this guy was into all kinds of other shady shit with really shady people.

      I am absolutely confident that idea of laced marijuana being sold to unaware consumers is an urban legend just like poisoned Halloween candy.

      And even if it were true, it would just be another argument in favor of legalization.

      1. Weed soaked in harmless DMT was popular and common in Dallas in the 1960s. Pseudoscientific politicians like Biden and Rubio got rid of that and replaced it with deadly fentanyl. The power to do that at gunpoint was handed to them by poltroons too cowardly to vote libertarian.

  11. What is Rubio smoking? Or is he just a worse mental case than Biden?

    1. I seriously doubt that is even possible. Biben's about as mentally gone as any semi-functioning human being can possibly be. Of course, that's with the possible exception of the people who actually voted for him. All 27 of them!

  12. Thats why you grow your own dummy!

    1. We grew our own dummy many times. Then we install them in office.

      1. Or they run off to the nearest bathhouse and become Tony.

  13. Is marijuana a gateway to other drugs?

    Where marijuana is still illegal a young person using the drug has to cross a big line. They have to go to the black market for the marijuana. I suggest that having crossed that line it is easier to continue to other black-market drugs. Were marijuana treated like alcohol an under 18 person would still have to cross a line to get the marijuana. But that line would not be in the black market but more likely, like alcohol from an older friend or sibling. While not ideal, they are probably not dealing with a person who might also offer them cocaine, heroin, or other harder drugs.

    1. So how does this line of thinking work when all drugs are pushed to the legal side of the line?

      Do gateway drugs just seize to exist?

      Color me skeptical to this line of thinking. I do think it breaks a barrier (like having sex for the first time), but it isn’t in crossing a legal boundary.

      1. Sockpuppets who cannot spell "cease" run little risk of serious consideration on a libertarian forum. Ambrose Bierce explained why:
        EDUCATION, n. That which discloses to the wise and disguises from the foolish their lack of understanding.

    2. It’s not much of a line.

    3. They cross the same line with alcohol.

      In any case, we have a giant mountain of evidence that suggests you're an utter moron for believing that crackpot theory.

      Perhaps you can explain why flat earthers are reasonable next.

  14. Don't treat Rubio's posturing as if it were what he really thought.

    Rubio is just signaling his stance/virtue/whatever that the strongest disapproval society can give to something is to have it illegal, and marijuana must be disapproved because it's associated with a demographic that old people can rally themselves in opposition to, and whatever, it's not something they need.

    However, his statement that people will conclude marijuana must not be so bad because it's been made legal is correct. People will conclude that, and they will conclude so correctly. Marijuana would not be legalized if it were known to be dangerous. So this is a valid heuristic.

    1. Roberta's hidden assumption is that to a coercive looter kleptocracy a human's life and happiness are some sort of standard of value. Rubio is precisely the sort of superstitious altruist that cannot even for a second conceive of anything but an invisible monster's whims as a standard that justifies the initiation of deadly force to enFORCE it. See Atlas Shrugged or Moral Rights and Political Freedom for detailed derivations, or minute 56 of: Harris v Craig http://www.youtube.com/watch?v=yqaHXKLRKzg

    2. Rubio is just signaling his stance/virtue/whatever that the strongest disapproval society can give to something is to have it illegal

      Correct. Rubio is a conservative.

      and marijuana must be disapproved because it's associated with a demographic that old people can rally themselves in opposition to, and whatever, it's not something they need

      I'm not sure what "demographic" you think you are talking about. Lots of older people use marijuana.

  15. I think science will show that weed is indeed, on balance, bad for people. Would that we had the ability to research it decades ago.

    But missing from this logic is the recognition that putting otherwise peaceful people in cages for years is also, to a degree, bad for people.

    1. Observe how wistfully the totalitarian mentality still pines for any pretext to pick up a gun and say: "We have tried this experiment, and determined every question involved in it. We have determined it, not only for ourselves, but for all others. And, as to all those who are weaker than we, we will coerce them to act in obedience to our conclusion. We will suffer no further experiment or inquiry by any one, and, consequently, no further acquisition of knowledge by anybody."--after Lysander Spooner, 1875

    2. It’s too soon to say. We need more studies on the effect of prisons on people before we embrace your crazy ideas about personal choice. Think of the children.

    3. But missing from this logic is the recognition that putting otherwise peaceful people in cages for years is also, to a degree, bad for people.

      But missing from your logic is the recognition that currently, taxpayers are forced to pay for the consequences of the harm caused by drug use. That's why socialist or socialist-leaning countries end up restricting drug use one way or another.

      The only way to have a society in which drug use is legalized is if individuals are forced to face the consequences of their drug use individually.

      As long as the US remains a social welfare state, drug legalization is a political gimmick for progressives, something that isn't sustainable as a policy.

      1. Yes I know, as long as the US is a social welfare state, we have no choice but to also be a totalitarian police state. The libertarian equation.

  16. "that people tend to use marijuana before other illegal drugs,"

    People tend to use tobacco, caffeine and alcohol before they use marijuana.

    1. People also tend to drink breast milk before moving onto any of these.

      1. You don't seem to understand the concept of a gateway drug. Infants drink mother's milk. The introduction to drugs like marijuana, caffeine, tobacco and alcohol happens typically in teenagers, at least a decade after infancy.

        1. I do understand the concept of a gateway drug. I’m just pointing out the absence of any evidence of a causal link in that concept.

          1. I'm sure there's no causal link. It's more a matter of a scale of social acceptability.

    2. What portion of tobacco/caffeine/alcohol users proceed to marijuana?

      What percentage of marijuana users proceed to Meth, coke, and heroin?

      1. MY cousin has a California Permit to obtain....
        "Medical Meth"
        (it helps with glaucoma...or somethin')

  17. Maybe it's a language problem. I am from a nearby island where an appropriate response would be que los Marlboros son legales y no contienen fentanilo, ¡bruto, pendejo, idiota!

  18. thanks for sharing this post

  19. thank you for best article

  20. A 2019 systematic review and meta-analysis in BMJ Open found the studies suggested "a small increase in cannabis use among adolescents and young adults following legalisation of cannabis for recreational purposes."

    Libertarian: drugs should be legalized no matter the consequences because of the NAP.

    Conservatives: drugs should be illegal in order to express the societal value that drug use is bad.

    Progressives: scientific studies show that legalizing drugs statistically reduces harm slightly.

    As usual, Reason comes down firmly on the progressive side of the argument. This can't even be rationalized as Reason trying to convince other groups, since progressives already favor drug legalization and since Reason's progressive argument fails to appeal to conservatives just as much as it fails to appeal to libertarians. Stop pretending that you are libertarians.

  21. Republicans worry that marijuana is a gateway to the metric system.

    1. Actually, the US is already on the metric system: units like "inch", "mile", "pound", etc. are defined in terms of the metric system.

    2. While liberals are still stuck in 1960s Time Warp.....
      insisting that pot smoke is "good for you"....while tobacco smoke is "produced by evil capitalists that know they are destroying the planet"
      OOOOOO.....have another Hit!! Of sweet California Sunshine!

  22. There is no fentanyl laced reefer. He is an idiot. No different than the gun control zealots that know nothing about guns.

    1. You honestly believe that?
      Kids these days.

      1. I think I misread your comment.
        You;re pointing out that reefer IS in fact laced with fentanyl(amoung other things used to increase "potency" and sales).
        Yes, I agree with that statement.
        The Kids are the ones that are insisting that marijuana is pure natural eco-friendly product that no produce would ever, ever think of adulterating.
        No....only evil tobacco growers do that.

  23. Here's the dilema......
    If we legalize pot, the main reason is to TAX it.
    But.....since pot sales have no trouble right now, when they are not paying any tax......why would any pot dealer voluntarily to start paying taxes???
    Thus pot remains "illegal" cuz they are paying any taxes.....and NOW ya gotta increase Law Enforcement anyway.
    Its a lose-lose proposition.
    And Jake....btw......you mean to say you DONT believe that pot is currently adulterated with all sorts of additives(including fentinyl)?????

  24. I'm sorta a dum-dum.....
    Some genius needs to explain to me how
    1. Tobacco smoke is bad for my lungs.
    2. Marijuana smoke is good for my lungs.

    1. It comes in edibles.

  25. Long ago, a science fiction writer, John Brunner, accurately saw the future.
    The Tobacco Industry is currently working on a method to control the distribution of marijuana......this is the choke point,,,,currently run by Criminal Gangs.....with the Govt TaxMan cut out of the loop.
    The Govt obtains no tax revenue from this lucrative business....
    Big Tobacco working with Big Govt is making the moves to destroy the Criminal Network that moves marijuana around the USA.
    With that accomplished,,,,expect to find legal hybrid cigarettes....tobacco + Marijuana on the market....everywhere.
    A drugged population is more apathetic and compliant with authoritarian government instructions.

  26. Holy Jesu this is something I did not think I would live to see:

    AOC-level dumb.

  27. If the black-market weed is laced with fentanyl, wouldn't it be better to displace that weed with white-market weed (which is laced with weed)?

    1. I was hoping someone would point this out. The answer is: "of course." While Marco is on our team, he's not on the starting lineup. Does a good job of keeping the bench warm, though.

  28. Sen. John Hickenlooper (D-CO) acknowledged that the fears he had that led him to campaign against Colorado’s legalization of marijuana when he was governor were misplaced. “I was pretty surprised that the data overwhelmingly showed again and again that youth use didn’t increase."

    1. What the youth do use is alcohol.

  29. Somebody needs to remind Rubio of how things went down when booze was again made legal. When it was prohibited, plenty of actors were moonshining, mainly for the profit. Many were not skilled, nor careful, nor scrupulous. Bad stuff was put into cans and bottles and sold. Many dies, went blind, had kidneys and livers pickled, etc. That all maguically went away when prohibition ended a few years later. Now a publically traded product, all the food prep and manufacturing standard were back in place. "red" 'shine disappeared.
    When cannabis is no longer black market, quality will be knowable, for one things, maintained to standards, for another, as sources will once again be traceable, and those selling "bad stuff" will be easily held to account.
    I am convinced one of the biggest deterrents to legalising pot is that the chinese will no logner be able to take their huge profits on black market "junk". Legal and safe will be vastly oreferred over cheap and skanky. Shops 'reputations" will be worth protecting when all is in the public eye.

  30. Everything that happens is a gateway (i.e. occurred prior to) to whatever happens afterwards.

    Intolerant Puritan prohibitionists have been falsely claiming that everything they want to ban (or keep banned) is a gateway to something else they also want to ban (or kept banned).

    According to the prohibitionists, abortion, drugs, sex, sex education, rock and roll, atheism, knowledge, free speech, etc. must all be banned (because they all are gateways to evil).

  31. The old gateway argument ????

Please to post comments

Comments are closed.