Senate Republicans are ready to escalate the war on drugs to deal with the country’s opioid crisis — despite decades of evidence that the approach just won’t work.

On Wednesday, the Senate Subcommittee on Crime and Terrorism discussed a bill that would reduce the threshold required to impose mandatory minimum sentences on people trafficking or distributing fentanyl, an opioid that has been increasingly linked to overdose deaths in recent years. The bill is backed by Sens. John Kennedy (R-LA), Tom Cotton (R-AR), Lindsey Graham (R-SC), Bill Cassidy (R-LA), Dean Heller (R-NV), Ben Sasse (R-NE), and Orrin Hatch (R-UT). It’s not clear, though, if it has the support — particularly the bipartisan support — that it needs to pass the full Senate.

The argument for the bill is the same as the argument for “tough on crime” policies of the past: The tougher criminal penalty would help deter drug dealers. That deterrence could then help, the senators believe, put an end to the opioid epidemic.

“There has to be some concept out there that if you’re hooked and you’re putting fentanyl into the stream of commerce — I mean the drug commerce — to feed your habit, then you’re not only a public safety hazard, that’s just wrong,” Graham said at Wednesday’s Senate hearing. “We’re gonna make people pay a heavier price for putting fentanyl into drugs knowingly — has to be knowingly. And that’s not going to cure the problem, but I think that it is a necessary step as part of a comprehensive strategy.”

During the hearing, senators claimed that current law is lopsided. They argued that it is currently possible to possess a lot of fentanyl — tens of grams — with an intent to distribute without triggering a mandatory minimum that would kick in for much lower amounts of equivalently deadly doses of other illicit substances. (For more on the hearing itself, Ames Grawert with the Brennan Center has a useful thread on Twitter breaking down the hearing in further detail.)

Of course, it would also be possible to make laws for different drugs more equivalent by increasing the thresholds for mandatory minimums for other substances — or eliminating mandatory minimums altogether.

Based on the empirical evidence and history, Senate Republicans’ proposal won’t work. Consider: We’ve had “tough” policies for illicit drugs for decades. Yet the country is still mired in the worst drug overdose crisis in US history, with drug overdoses killing an all-time high of nearly 64,000 people in 2016 and preliminary data suggesting that 2017 was even worse.

The “tough on crime” approach does not work

As Graham suggested, the idea behind the “tough on crime” approach to drugs is to increase the price on dealing drugs. This is actually a bit literal: Part of the thinking is that if you crack down on drug dealers and traffickers, you can reduce the available supply of illicit substances, which makes these drugs more costly. That, in turn, makes drug use more expensive — so fewer people will be able to initiate or continue using drugs.

This concept, though, falls apart in reality. As Mark Kleiman, a drug policy expert at the Marron Institute at New York University, previously told me, “We did the experiment. In 1980, we had about 15,000 people behind bars for drug dealing. And now we have about 450,000 people behind bars for drug dealing. And the prices of all major drugs are down dramatically. So if the question is do longer sentences lead to a higher drug price and therefore less drug consumption, the answer is no.”

One of the best studies backing this is a 2014 review of the research by Peter Reuter at the University of Maryland and Harold Pollack at the University of Chicago. They found that while simply prohibiting drugs to some extent does raise their prices, there’s no good evidence that tougher punishments or harsher supply elimination efforts do a better job of driving down access to drugs and substance misuse than lighter penalties. So increasing the severity of the punishment doesn’t do much, if anything, to slow the flow of drugs.

This applies more broadly, not just to drug crimes. The research has suggested that harsher punishments in general don’t do much to prevent crime. As the National Institute of Justice concluded in 2016, “Research shows clearly that the chance of being caught is a vastly more effective deterrent than even draconian punishment. … Research has found evidence that prison can exacerbate, not reduce, recidivism. Prisons themselves may be schools for learning to commit crimes.”

In other words, more certainty of punishment can deter crime, while more severity — through longer sentences that expose people to prison for longer periods of time — can actually make crime worse.

Harsher punishments can also be counterproductive by punishing the people who need addiction treatment, not incarceration. Although many of these efforts are framed as going after drug dealers and traffickers, the line between who is a dealer or trafficker versus a user is often blurry. A 2017 Bureau of Justice Statistics report, for instance, found that “nearly a third of drug offenders (30 percent of state prisoners and 29 percent of jail inmates) said they committed the offense to get drugs or money for drugs.”

But Graham suggested that locking up opioid users is a feature of the policy, not a bug — arguing that if you are “hooked” and trafficking fentanyl to “feed your habit,” you should be punished. While that might lock up some drug dealers, this misses the root problem — the drug addiction — that needs to be dealt with. (For one, most prison systems don’t offer adequate access to treatment to inmates.) That’s one reason experts have argued that to deal with the opioid crisis, a public health approach, not a criminal justice one, is necessary.

Experts want a public health approach

If you ask experts what to do about the opioid crisis, the first answer you’ll typically get is more treatment, particularly more access to anti-addiction medications like methadone and buprenorphine. You also will hear about harm reduction efforts, such as increasing access to the opioid overdose antidote naloxone. And you might hear about efforts to reduce other sources of demand — particularly the root causes of addiction, such as mental health issues and stagnant socioeconomic conditions.

More incarceration almost never comes up — and if it does, it’s usually in a negative light. As Sarah Wakeman, medical director at the Massachusetts General Hospital Substance Use Disorder Initiative, previously told me, “greater criminalization would be not only ineffective but actually harmful” — by promoting a stigma that can deter people from seeking help for drug addiction.

Beyond the potential harms of more stigmatization, the reality is that locking up more people costs money. In a world with limited resources, the limited pool of funds should go to policies that are backed by evidence and experts — not an approach that probably won’t work and especially one that has demonstrably not worked in the past.

So how would experts want to spend the limited pool of money? Earlier this year, Josh Katz at the New York Times put it to the test: He asked 30 experts how they’d spend $100 billion over five years on the opioid epidemic. On average, experts said that 47 percent of the money should go to treatment, 15 percent to harm reduction, and 27 percent to demand (with a focus on “community development” to address the root causes of addiction).

The addiction treatment money in particular would go to a serious problem: According to a 2016 report by the surgeon general, about 10 percent of people in the US with a drug use disorder get specialty treatment — which the report attributed to a lack of access to care. And even when treatment is available, other federal data suggests that fewer than half of facilities offer opioid addiction medications like methadone and buprenorphine, which are considered the gold standard of treatment and, studies show, cut mortality among opioid addiction patients by half or more.

Meanwhile, experts said that only 11 percent should go to supply, which can include the kind of punitive criminal justice efforts that the Senate fentanyl bill is going for. The bulk of even this limited supply money, however, went to prescription monitoring and reducing diversion of opioid painkillers by, for example, putting more money toward drug take-back initiatives to discard unused opioids. So even this pot of money wasn’t focused on more mandatory minimums.

This shouldn’t be too surprising. At this point, it has become a cliché in the opioid epidemic for experts and officials to say that “we can’t arrest our way out of this.” Yet even as people say that over and over again, Senate Republicans are pushing lock up more people, even those who are addicted and need treatment, as part of their efforts to end the opioid crisis.