Are the past year's examples of racially charged police abuses from Ferguson to Staten Island to North Charleston affecting the Supreme Court? In a subtle way, the answer may well be yes.
In the first evidence of an effect, the Supreme Court held Tuesday that a traffic stop can't be prolonged beyond the time that the police need to perform their basic functions. In a 6-3 opinion, the court said police can't perform a canine drug-sniff after a ticket has been issued -- even though, a decade ago, it held that a drug sniff that occurs during a lawful stop is perfectly constitutional.
On the surface, the court's distinction between the two scenarios depends on whether the dog sniff extends the length of the traffic stop.
Underneath, however, it's possible to discern a subtly changing attitude on stop-and-frisk policing, the centerpiece of the broken-windows approach. Where once the court saw the practice as unproblematic, today the court seems more willing to police the policing process -- and make sure it doesn't become abusive.
Legally speaking, Tuesday's case had nothing to do with race. In a 2005 case called Illinois v. Caballes, the court had held that police could conduct a canine drug sniff of the exterior of your car when you were stopped for speeding. In that case, the drug sniff didn't extend the length of the stop. The decision was 7-2, with then-Justice John Paul Stevens, a leading liberal, writing the opinion. Justices Ruth Bader Ginsburg and David Souter dissented. Ginsburg argued that the search should have a reasonable relation to the stop.
Lower courts interpreting the Supreme Court's precedent then split on the question that wasn't fully answered in the Caballes case: Could police extend an already legitimate police stop to conduct a drug sniff, absent "reasonable suspicion" of drugs?
The court took the case Rodriguez v. United States to answer that question and resolve the circuit split. This time, however, Ginsburg got to write the majority opinion. She didn't overturn the 2005 Caballes case, in which she had dissented -- doubtless she didn't have the votes to do so. Instead, she noted that Stevens, writing in Caballes, had said that a traffic stop could become unlawful "if it is prolonged beyond the time reasonably required to complete the mission of issuing a warning ticket."
Ginsburg was this time prepared to concede that an officer could perform "certain unrelated checks" during a traffic stop. But, she said, the officer could not perform unrelated checks "in a way that prolongs the stop."
In purely technical legal terms, this was a clever move by Ginsburg. Unable to convince her colleagues that searches conducted during a stop must be reasonably related to the stop itself, she managed to convince them that searches extending the length of the time of the stop must be justified by independent reasonable suspicion -- because they are not "part of the officer's traffic mission." In other words, she got some of what she wanted in 2005 by using the notion of extended time. Now unrelated searches can only be performed if they won't extend the length of the stop.
Ginsburg's doctrinal sleight of hand underscores the idea that there is an important, even fundamental, difference between the pro-police result in the 2005 case and the result reached Tuesday. What explains the other justices' willingness essentially to flip, or at least to adopt a more restrictive stance regarding traffic stops?
The most powerful answer is that the court is well aware of a more complex public attitude toward stop-and-frisk policing, the cornerstone of the broken-windows strategy that is generally given some portion of the credit for declining crime rates in urban spaces over past two decades.
After all, the basic rationale for having a dog sniff the car of a person stopped for an unrelated traffic violation is exactly the broken-windows rationale, namely that people who have committed a minor infraction of one kind may be found committing a more serious violation of another kind, one that would lead to arrest. The drug sniff pursuant to a traffic stop is therefore a perfect example of the policy -- and a perfect test case for changing attitudes.
It can't have escaped the court's attention that several of the killings of black men by police came in the wake of broken- windows-style stops. Most recently, Officer Michael Slager's fatal encounter with Walter Scott in North Charleston, South Carolina, began with a traffic stop. Scott's family says he probably fled because he had an unrelated warrant for failing to pay child support -- again, a classic instance of the broken- windows rationale in action.
The justices prefer not to acknowledge that they are affected by national social movements such as the "Black Lives Matter" and "We Can't Breathe" marches. Not long ago, I asked Justice Stephen Breyer in a public interview whether he thought the justices might be affected by this movement. He gracefully dodged the question.
But the justices follow the news, and are affected by changing social attitudes like anybody else. Today, a reasonable observer who isn't personally subject to broken-windows policing -- someone like the justices, in other words -- must be more conscious of the risks of excessive police engagement in the lives of citizens, especially racial minorities.
The justices can't change policing practices single-handedly, nor would they choose to if they could. But Tuesday's decision suggests that the judicial pendulum may be beginning to move. The first movement may seem small. But the pendulum tends to have momentum.
Noah Feldman, a Bloomberg View columnist, is a professor of constitutional and international law at Harvard.