Barack Obama, as chief law enforcement officer of the United States, is going to have to stop acting like a conscientious objector in this war on cops.

Wednesday, another officer, in Fox Lake, Illinois, Lt. Charles "GI Joe" Gliniewicz, was gunned down. Last Friday, Darren Goforth, a Houston deputy sheriff, was shot 15 times by an alleged black racist.

President Obama called the widow of Deputy Goforth, but he has yet to show the same indignation and outrage he exhibited at what happened to Trayvon Martin in Florida and Michael Brown in Ferguson.

This year, 24 cops have been gunned down. And the day after deputy Goforth's execution, "Black Lives Matter!" showed up at the Minnesota state fair chanting, "Pigs in a blanket! Fry 'em like bacon!"

Last fall, when mobs blocked highways after the death of Eric Garner in an encounter with police on Staten Island, the hoodlum chant was: "What do we want? Dead cops! When do we want 'em? Now!"

Soon after, two cops in Brooklyn were executed in their patrol car.

Time for Obama to ascend the bully pulpit and call out the racial demagogues in the fever swamps of his own radical left constituency.

For some of the evils of the last century we thought we left behind seem to be returning, as is the old indulgence of lawlessness when done by those claiming some "grievance" against society.

Violent crime is rising again, a direct result, many believe, of a new police reluctance to be aggressive in enforcing the law, to avoid violent clashes with criminals and suspects, the so-called "Ferguson effect."

The lead story in the Sept. 1 New York Times reported a surge in murders in the city after the Eric Garner incident, and even greater surges in Milwaukee, St. Louis, Baltimore, Washington, D.C., and Chicago.

A closer look at the Times figures reveals something more disturbing. Chicago, a city with not half the population of New York, exceeds New York in murders this year, 294 to 208.

Washington, a city not a tenth as populous as New York, had half as many murders, 105. Baltimore, where Freddie Gray died in police custody, and six officers have been charged in his death, has had more murders this year, 215, than New York, though New York has 14 times the population.

To discover the causes of the new crime wave in America, we should reconsider what rolled back the tsunami of crime that swept America from the 1960s to the early 1990s.

One of the causes of that crime wave was simple demography. From 1962 to 1990, the baby-boom generation, largest in U.S. history, passed into, through, and out of that age cohort, 18 to 36, where crime among males is at its highest.

Second, beginning with the Reagan era around 1980, America nearly quadrupled the number of incarcerated, from 600,000 to over 2 million in jails and prisons. Muggers, robbers, rapists, killers were taken off the streets and put away for decades.

With mayors like Rudy Giuliani, hard-core criminals had the book thrown at them, and even petty crimes were prosecuted before the petty criminals graduated to worse crimes.

Cops became heroes. America's cities became livable again.

Washington ceased to be the "murder capital of the nation." Young people begin moving in and fixing up inner-city neighborhoods that few had dared to visit a couple years before.

While we have nowhere near the murders, rapes and robberies we did in the worst decades of the 20th century, the crime rate is rising across the nation.

In D.C., restrictions on cops and a spike in crime have produced a huge vote of no confidence from the Fraternal Order of Police in once-popular Police Chief Cathy Lanier.

Cops say that aggressive methods of crime control like New York's "stop and frisk" make cities safer. The D.C. Fraternal Order says that city leaders need to "stop sacrificing the safety of our communities ... to political correctness," and let the cops do their jobs.

Post-Ferguson, America seems to be dividing angrily over this issue of cops and crime.

The Right sees America's cops as civilization's last line of defense against crime and anarchy. Among liberal elites and the Black Lives Matter crowd, an old notion is regaining ascendancy -- cops are the problem and police are all too often the oppressors.

In the 1960s, Vice President Hubert Humphrey declared that if he had to endure the conditions of the ghetto, he "could lead a pretty good riot" himself, while Nixon ridiculed the Kerner Commission report that blamed the riots on "white racism."

Nixon and George Wallace got 57 percent of the vote in 1968. And a strong stand for law and order helped to give the GOP a near quarter-century lock on the presidency.

The law and order issue is lying there again, waiting to be picked up.

Meanwhile we ought to hear from our president about who and what he thinks is responsible for all those wounded and dead cops.