Now that the Obama administration and much of the political right is on board with reform, we may have finally turned a corner with respect to harmful, unjust, completely irrational sentences we’ve been imposing on people convicted of drug offenses. But there’s another aspect to drug sentencing that’s just as ridiculous but hasn’t received nearly as much attention — the way authorities weight the quantity of a drug when determining how to charge someone.

Former federal prosecutor Mark Osler explains in the New York Times:

We continue to use the weight of narcotics as a proxy for the culpability of an individual defendant, despite this policy’s utter failure. If a kingpin imports 15 kilograms of cocaine into the country and pays a trucker $400 to carry it, they both face the same potential sentence. That’s because the laws peg minimum and maximum sentences to the weight of the drugs at issue rather than to the actual role and responsibility of the defendant. It’s a lousy system, and one that has produced unjust sentences for too many low-level offenders, created racial disparities and crowded our prisons . . .

Some laws create remarkably low thresholds for the highest penalties. For example, my home state of Minnesota categorizes someone who sells just 10 grams of powder cocaine (the equivalent of 10 sugar packets) as guilty of a first-degree controlled-substance crime — the most serious of five felony categories. There is no real differentiation between the most culpable wholesaler and an occasional street dealer.

The problem with recent legal reforms is that they don’t dispose of this rotten infrastructure. In 2010, Congress passed the Fair Sentencing Act, which changed the ratio between crack and powder cocaine for sentencing purposes from 100-to-1 (meaning the same sentence applied to 100 grams of powder cocaine and to 1 gram of crack) to 18-to-1.

What the Fair Sentencing Act didn’t do is change the basic weight-centric focus that has filled our prisons with narcotics convicts. There were 4,749 such prisoners serving federal time in 1980, before the harshest weight-based standards were implemented. As of 2013, that number was 100,026. As for the drugs themselves, they’re still here.

The law compounds this problem by considering all members of a supposed conspiracy to be equally responsible.

Another problem that Osler doesn’t discuss is that when it comes to what is weighed in these cases, the laws are written in ways that maximize culpability. For example, when Florida pain patient Richard Paey was arrested for illegally obtaining painkillers containing oxycodone, prosecutors charged him with possessing more than 28 grams of the drug, which allowed them to charge him with trafficking instead of mere possession, despite the fact that by all accounts, Paey had obtained the pills solely to treat his own pain. But the pills Paey possessed were 98 percent acetaminophen, a legal, over-the-counter medication. Under Florida law, if the pill contains both legal and illegal substances, the state can charge you as if everything in the pill is illegal.

This is also true of non-prescription drugs. A hit of LSD dissolved in a sugar cube will weigh exponentially more than the same hit dissolved into blotter paper. But in most states, it’s the total weight that matters, not the weight of the actual LSD. (The U.S. Supreme Court has upheld the policy.) The same is often true of cocaine. A pound of pure cocaine is obviously much more valuable and has the potential to get a lot more people high than a pound of a substance consisting of cornstarch and a small amount of cocaine. But many states treat them the same (though in some federal circuits, at least with cocaine, the two are now treated differently). In some states, whether or not you’ve just harvested your pot plants could determine whether you’re charged with a misdemeanor or a felony. Ironically, if the plant is unharvested, the police can charge you for the weight of the entire plant, while if you’ve just harvested, dried and sold the leaves, you’re less culpable.

What’s clear from all of this is that today’s drug laws were written in an era in which lawmakers were less concerned about rationality, harm prevention and punishment that is proportional to the alleged harm done. Rather, they wrote the laws in ways that give prosecutors the most power to put the most people in prison for as long as possible.