Baltimore is now paying the price for irresponsible words and actions, not only by young thugs in the streets, but also by its mayor and the state prosecutor, both of whom threw the police to the wolves, in order to curry favor with local voters.

Now murders in Baltimore in May have been more than double what they were in May last year, and higher than in any May in the past 15 years. Meanwhile, the number of arrests is down by more than 50 percent.

Various other communities across the country are experiencing very similar explosions of crime and reductions of arrests, in the wake of anti-police mob rampages from coast to coast that the media sanitize as "protests."

None of this should be surprising. In her carefully researched 2010 book, "Are Cops Racist?" Heather Mac Donald pointed out that, after anti-police campaigns, cops tended to do less policing and criminals tended to commit more crimes.

If all this has been known for years, why do the same mistakes keep getting made?

Mainly because it is not a mistake for those people who are looking out for their own political careers. Critics who accuse the mayor of Baltimore and the Maryland prosecutor of incompetence, for their irresponsible words and actions, are ignoring the possibility that these two elected officials are protecting and promoting their own chances of remaining in office or of moving on up to higher offices.

Racial demagoguery gains votes for politicians, money for race hustling lawyers and a combination of money, power and notoriety for armies of professional activists, ideologues and shakedown artists.

So let's not be so quick to say that people are incompetent when they say things that make no sense to us. Attacking the police makes sense in terms of politicians' personal interests, and often in terms of the media's personal interests or ideological leanings, even if what they say bears little or no resemblance to the facts.

Of course, all these benefits have costs. There is no free lunch. But the costs are paid by others, including men, women and children who are paying with their lives in ghettos around the country, as politicians think of ever more ways they can restrict or scapegoat the police.

The Obama administration's Department of Justice has been leading the charge, when it comes to presuming the police to be guilty -- not only until proven innocent, but even after grand juries have gone over all the facts and acquitted the police.

Not only Attorney General Holder, but President Obama himself, has repeatedly come out with public statements against the police in racial cases, long before the full facts were known. Nor have they confined their intervention to inflammatory words.

The Department of Justice has threatened various local police departments with lawsuits unless they adopt the federal government's ideas about how police work should be done.

The high cost of lawsuits virtually guarantees that the local police department is going to have to settle the case by bowing to the Justice Department's demands -- not on the merits, but because the federal government has a lot more money than a local police department, and can litigate the case until the local police department runs out of the money needed to do their work.

By and large, what the federal government imposes on local police departments may be summarized as kinder, gentler policing. This is not a new idea, nor an idea that has not been tested in practice.

It was tested in New York under Mayor David Dinkins more than 20 years ago. The opposite approach was also tested when Dinkins was succeeded as mayor by Rudolph Giuliani, who imposed tough policing policies -- which brought the murder rate down to a fraction of what it had been under Dinkins.

Unfortunately, when some people experience years of safety, they assume that means that there are no dangers. That is why New York's current mayor is moving back in the direction of Mayor Dinkins. It is also the politically expedient thing to do.

And innocent men, women and children -- most of them black -- will pay with their lives in New York, as they have in Baltimore and elsewhere.