Two of the big legal stories of the past few weeks seem, on the surface, to have almost nothing to do with one another. Attorney General Eric Holder gave a tentative acquiescence to the marijuana-legalization programs in the states of Colorado and Washington. A federal judge declared that the stop-and-frisk practices of the New York Police Department violated the Constitution.

In truth, the two decisions are closely related and suggest a welcome injection of sanity into contemporary American law enforcement.

Holder acted in response to the legal uncertainty created by two voter initiatives on marijuana, which made pot legal under state law but left its possession and distribution illegal under federal law. Holder came up with a reasonable compromise, which amounted to putting Washington and Colorado on a kind of probation. Holder said, in effect, that as long as the states kept pot away from kids, policed drugged driving, and kept the distribution away from narcotics cartels, the feds would leave the states alone.

Holder’s decision, and the reaction to it, suggests the changing political reality around marijuana. Even many tough-on-crime conservatives have come to recognize the futility (and vast expense) of the drug war. Putting people in prison for possession, or even for distribution, of marijuana seems increasingly like a form of cruel madness. Holder is the most politically controversial member of President Obama’s Cabinet, the frequent target of Republican attacks in Congress, and yet his decision on pot was met with silence. (Mostly.) If the Washington and Colorado experiments proceed successfully, it’s a certainty that other states will follow. And Holder’s decision suggests, too, that the federal government will continue to back away from bringing marijuana cases.

This is where the stop-and-frisk connection comes in. Judge Shira Scheindlin’s exhaustive opinion concluded that the N.Y.P.D. had engaged in an unconstitutional dragnet that subjected far too many innocent people to scrutiny. (During the stop-and-frisk trial, in May, I profiled Judge Scheindlin in the magazine.) The stops were designed principally to locate weapons, but in more than ninety-eight per cent of the 2.3 million frisks, no weapon was found. Of the larger number of 4.4 million stops, only six per cent resulted in an arrest, and six per cent resulted in a summons. (Not all stops led to frisks, thus the difference in the numbers.) The remaining stops resulted in no further law-enforcement action at all.

Most importantly, the judge found that the police targeted minorities with its stop-and-frisk tactics. In fifty-two per cent of the 4.4 million stops, the person stopped was black, in thirty-one percent the person was Hispanic, and in ten per cent the person was white. (In 2010, New York City’s resident population was roughly twenty-three per cent black, twenty-nine per cent Hispanic, and thirty-three per cent white.) In all, Judge Scheindlin concluded, “these results show that blacks are likely targeted for stops based on a lesser degree of objectively founded suspicion than whites.”

Scheindlin herself drew the connection between stop-and-frisk and marijuana arrests. As she noted, “the most common arrest after a stop is for marijuana possession.” And this is where the two stories intersect, or rather collide.

To put the matter simply, blacks are at far greater risk of arrest for marijuana than whites are. This means that a black teen-ager in Brownsville, for example, is a great deal more likely than a white teen-ager in Park Slope to embark on adulthood with the added disadvantage of a drug record, even if their experiences with marijuana are exactly the same. Black folks who smoke on the street risk arrest; white yuppies who relax with a joint after work do not. Indeed, a recent federal study showed that blacks were nearly four times as likely as whites to be arrested on charges of marijuana possession in 2010, even though the two groups use the drug at similar rates. This study is essentially the Scheindlin decision on a national scale. It showed that the rate of marijuana arrests had actually increased since Obama became President.

But Holder’s decision suggests (though it does not guarantee) that marijuana arrests will be heading downward. To the extent that they do, that will be a step forward for racial equality. Ending discriminatory enforcement—which is what happened in New York and around the country—is a positive step for everyone.

The drug war is sometimes portrayed as irrational, but it is, in fact, irrational in a selective way—one targeted at blacks and other minorities. The decisions by Holder and Scheindlin point the war, and the country, back in a direction where law enforcement will spend more time chasing the right people for the right reasons.

Photograph by Justin Sullivan/Getty.