One thing to expect following Donald Trump’s endorsement of stop, question, and frisk as a tactic to use against crime is that we’re going to hear that at New York it was found to be unconstitutional. Whether Hillary Clinton will take the bait is not yet clear. According to the Reuters wire, stop, question, and frisk has been the target of “successful legal challenges in New York.” Then again, too, it depends what one means by “successful.”

There is no doubt that the stop, question, and frisk program used by Mayor Bloomberg and Commissioner Kelly of the New York Police Department was ruled unconstitutional by United States District Judge Shira Scheindlin. She, however, was cashiered from the case for failing to maintain an appearance of impartiality. This was done by three appeals judges who ride the 2nd United States Circuit. A second district judge then ruled the same way Judge Scheindlin had.

The thing to mark about this case is that the only reason those rulings were never overturned on constitutional grounds is that Mayor de Blasio abandoned the defense of the NYPD and the policies of his predecessor and settled the case. There was little doubt to anyone in the courtroom during the early hearings on the matter in the 2nd Circuit that had His Honor pressed the appeal, the sages would have put paid to Judge Scheindlin’s whole scheme.

One can never be certain, of course, what a court might have done. But Commissioner Kelly expressed in his memoir his belief that the city would have won the appeal had it pressed it. That is also the view of the correspondent of the Sun who was in the courtroom when the 2nd Circuit heard early arguments. These columns thought finding a way to gain appellate review of the constitutional issues was important, not only to clear the good name of the Mayor and the NYPD but to preserve the city’s future freedom of action against crime.

Too, not all stop, question, and frisk programs were ruled unconstitutional by the lower courts. The tactic is as old as policing, a point that has been marked on several occasions by one of Mr. Kelly’s predecessors and his successor, Commissioner Bratton. And it wouldn’t be surprising to see some form of stop, question, and frisk come back into widespread use once the crime rate starts to rise again in New York from the depths to which Messrs. Kelly and Bratton brought it.

All New Yorkers, of every creed and color, benefitted from the war on crime that the two commissioners and Mayors Dinkins, Giuliani, and Bloomberg led. Mr. Trump is right, though, in marking that no group has benefitted any more than the minority communities, who have been the victims of so much crime. Given the default by Mayor de Blasio in failing to seek proper appellate review of the city’s program, it can be said that Mr. Trump is opening an important question when he suggests that stop, question, and frisk might be useful beyond New York City.