Conservatives took a break last week from their sensible skepticism toward big government in order to embrace the liberal logic of gun control. That logic is familiar to anyone who has ever spent much time kibitzing the gun debate, and it goes like this: Government should infringe, or even abrogate, the rights of millions of law-abiding people in order to stop a minuscule fraction who use guns to commit mayhem.

Whether gun-control laws actually produce the desired results is a matter of great dispute. But liberals will happily cherry-pick the data that best make their case. (Why should they be any different?) They will then argue as The New York Times did in 2010, when it denounced a Supreme Court ruling upholding gun rights: "The arguments that led to Monday's decision," the newspaper intoned, "were infuriatingly abstract, but the results will be all too real and bloody."

Translation: Don't give us any of that airy nonsense about rights. People's lives are on the line here. This, in essence, was how conservatives reacted last week when a federal judge said New York's stop-and-frisk tactics were unconstitutional.

Stop-and-frisk was "a policy that has saved thousands of black lives," wrote noted civil-rights icon Ann Coulter. The Wall Street Journal agreed: "If the judge's ruling isn't overturned, the victims won't be in the tony precincts [but] in the barrios and housing projects." Channeling The Times, Daniel Henninger of The Journal griped that "when liberals weigh the reality of physical threat . . . against hyper-abstract interpretations of constitutional rights, abstraction wins."

According to National Review, "intelligent police work" had "reversed what seemed 20 years ago to be an inescapable descent into lawlessness, indecency, and chaos." Writing in City Journal, Heather Mac Donald concurred: "New York's 20-year reprieve from debilitating violence may well be over." She fretted the ruling could "signal the end of the freedom from fear that New York's most vulnerable residents have enjoyed." In Commentary, Seth Mandel depicted stop-and-frisk as a "fight to keep the city's minority neighborhoods safe."

And, sure, that might be the intent. But then you can claim all sorts of policies will keep a city safe, including a total ban on firearms and surprise house-to-house searches for drugs. If the ends justify the means, then you can do just about anything you want. Conservatives usually like to think they're a little more high-minded than that.

The other trouble with such consequentialist rationales is that they depend on producing the right consequences. So naturally, conservatives simply assume stop-and-frisk deserves the lion's share of the credit for New York's falling crime rate. But crime has fallen steeply across the country – including in many places that did not employ stop-and-frisk.

What's more, conservatives seem to have forgotten their own prior explanation for the Big Apple's progress: the broken-windows theory. That theory, popularized by the late James Q. Wilson, posited that tolerating minor crime such as turnstile-jumping and vandalism created an atmosphere major crime found inviting. To discourage major crime, therefore, crack down on petty crime. You can read volumes on how "James Q. Wilson's thinking about crime and policing saved lives and transformed cities for the better" in the City Journal article "Man of Reason" (by Heather Mac Donald) – and several others just like it.

Mac Donald now defends stop-and-frisk by pointing out blacks and Hispanics are the primary perpetrators of violent crime in New York – so it only stands to reason that they should be the primary targets of stopping and frisking. This epitomizes the racial-profiling fallacy you also see in the debate over Muslims and terrorism.

It's undeniably true that Muslims have committed most of the terrorist attacks against the U.S. in the past couple of decades. But this does not justify viewing all Muslims with suspicion, because while there have been only a handful of attacks, there are something like 1.6 billion Muslims. The odds that any one of them is a terrorist is, therefore, vanishingly small. (Not surprisingly, the same NYPD that carries out stop-and-frisk got into hot water a couple years ago for infiltrating mosques and other Islamic institutions.)

By the same token, just because most perpetrators in New York are black or Hispanic does not mean most blacks or Hispanics are perpetrators. After all, most homicides are committed with guns – but that does not mean most gun owners commit homicide.

The NYPD's defenders also contend the police did not stop and frisk minorities at random; they stopped those who acted suspiciously. This is true only if you consider perfectly normal behavior suspicious. Judge Shira Scheindlin found, for instance, that (as a news account put it) "officers sometimes stopped people on the grounds that the officer observed a bulge in the person's pocket; often it turned out that the bulge was caused not by a gun but by a wallet." Other causes for suspicion: "being fidgety" and "walking in a certain way." That sounds ironclad, doesn't it?

In fact, stop-and-frisk is not a tremendous success but a tremendous failure, because such stops turn up contraband only 2 percent of the time. In other words: 98 times out of 100 the officer's suspicion is unjustified.

If any other program had a 98 percent failure rate, conservatives would hold it up as a shining example of everything that's wrong with big government. That they're so eager to defend a failing program when it happens to target minorities makes their professed concern for "the most vulnerable" ring a trifle hollow.

This column originally appeared in the Richmond Times-Dispatch.