The Supreme Court said the city of New Haven did it wrong. But the bare majority of the highest court in the land did little to help those cities that want to do it right.

“It” in this case is the process of hiring and promoting public employees, specifically firefighters, in a way that does not discriminate against either whites or minorities. The lack of guidance offered by the 5-4 majority leaves governments, as well as private employers, to continue searching for a means of picking winners and losers that offends neither federal law nor any fundamental sense of fairness.

New Haven city officials were clearly in an unenviable position in 2003 when they gave a written test to internal applicants for 15 open billets for fire lieutenants and captains and found that none of those who scored high enough to win promotion was black. In a city where most of the population is black or Hispanic, the threat of lawsuits was enough to make the city throw the test out and start over.

But the white firefighters who would have been promoted based on the test sued. They lost before the U. S. District Court and 2nd Circuit Court of Appeals, but convinced swing Justice Anthony Kennedy and the four members of the court’s conservative bloc that they had been wronged.

New Haven, Kennedy wrote, was not under any court order or facing any live lawsuit demanding redress for past discrimination against minorities. It had no evidence that the test the city used was biased against minorities, in fact having gone to some pains to make sure the test was race-neutral. Thus, he said, the city’s action amounted to an illegal act of reverse discrimination.

But both Kennedy and Justice Ruth Bader Ginsburg, who wrote in dissent, noted that the ruling does not explain what other means of judging fitness, under what other circumstances, would pass constitutional muster.

The ruling does not, for example, settle a similar case long pending against the Buffalo Fire Department. Here, the city also abandoned the results of a promotion exam when its results did not lead to the promotion of enough minority hopefuls. But it did so under different circumstances, laboring under lawsuits alleging, and at least one court having found, past discrimination against minorities that the city was supposed to be redressing.

One promising alternative, as reported in the New York Times, is a growing practice among cities to base promotion of public safety workers on simulations rather than written tests. In theory, simulations provide a better measure of which applicants would better be able to put out a fire or arrest a drunk. In practice, we are told, such tests do a better job of producing fire and police departments that resemble the racial mix of the communities they serve.

Those are all questions that New Haven, Buffalo and other communities across the country are going to have to keep wrestling with. Because a fractured high court, led by a chief who prefers to make his rulings as narrow as possible, is not going to come to their rescue.