The Senate's revised bipartisan criminal justice reform bill, spearheaded by Sen. Chuck Grassley (R-IA), suggests at least some federal lawmakers have truly learned nothing from the failures of the war on drugs.

In an effort to make the bill more palatable to conservatives, Reuter reports that the Senate is making several changes. The good news is it still keeps many of the provisions that let nonviolent offenders, including those imprisoned or charged for drug crimes, get an early release or shorter sentence. Even as the bill gets watered down, supporters have always been able to argue that it will at least do this correctly.

But even on this front, the bill now makes a huge misstep with one new addition. Joel Gehrke explained for the Washington Examiner: "Some Senate Republicans might also be drawn to the bill by the inclusion of 'a mandatory sentencing enhancement for fentanyl crimes,' an addition that could be particular appealing to Sen. Kelly Ayotte, whose home state of New Hampshire is struggling to contain a heroin epidemic."

This is troubling, not least because it's the exact kind of "tough on crime" reaction that fueled the war on drugs and led America to become the world's leader in incarceration.

The criminal justice reform bill now reacts to a drug epidemic with "tough on crime" policies

The ongoing opioid painkiller and heroin epidemic has provided lawmakers a chance to show if they've learned the lesson of previous government reactions to drug epidemics — mainly, that tougher punishments don't really work.

In the 1990s, doctors opened up access to opioid painkillers, getting many patients hooked on the drugs. So when officials pulled back access to painkillers, many addicted users didn't just quit the drug; they moved to another opioid, heroin. And now, there are signs that some opioid users are moving on to an opioid that's more powerful and potentially cheaper than painkillers or heroin, fentanyl. And that's all causing more overdose deaths. (For more on the opioid epidemic, check out Vox's explainer.)

The criminal justice reform bill's solution to this epidemic? A harsher punishment. And that means more nonviolent drug offenders will end up behind bars for long periods of time — particularly for fentanyl.

This defies the big lesson of the drug war's failures.

This defies the big lesson of the drug war's failures. In fact, it's essentially a repeat of how we got here.

In fact, it's essentially a repeat of how we got here: In the 1980s and 1990s, federal lawmakers reacted to the crack cocaine epidemic with very harsh penalties — particularly mandatory minimum sentences — for crack and, to a lesser extent, other drugs. What followed was a rise in incarceration, driven in part by (but not entirely) stiffer drug sentences.

Criminal justice experts generally agree this has been a disaster. America now leads the world in incarceration, but the research shows that incarceration played a minor role in the massive crime drop that began in the '90s.

A 2014 study from Peter Reuter at the University of Maryland and Harold Pollack at the University of Chicago found that there's no good evidence that tougher punishments do a better job of pushing down access to drugs and substance abuse than lighter penalties. So just making drugs illegal likely makes them less accessible, but increasing the punishment linked to those drugs doesn't deter their use and trafficking.

Kevin Ring, a former congressional aide who helped enact mandatory minimums and now speaks out against them through the advocacy group Families Against Mandatory Minimums, put it another way: "Most of these guys made stupid mistakes without any idea of what the punishment was — they just didn't think they were going to get caught. So you can make the severity off the charts — you can do a life sentence for jaywalking — it's not going to stop it."

But the new fentanyl provision shows that many lawmakers are still wedded to the idea that appearing "tough on crime" is a good way to fight crime — to the point that reacting to another drug epidemic with punitiveness is seen as a potential way to win votes for the Senate's reform bill.

It's possible that, on net, the criminal justice reform bill still ends up doing more good than harm — by potentially reducing incarceration more than it increases it. But even if that's the case, the fact that some senators are once again reacting to a drug epidemic with more "tough on crime" policies shows there's still a lot of work to do on the reform front.