Back in April, the Department of Justice sought to prevent illegal border crossing with a “zero tolerance” policy that involved a large expansion of criminal prosecutions. By June, holding facilities in Texas were packed, and pictures of crying children separated from parents hijacked any rational explanations, forcing President Trump to put the policy on hold.

The move stopped the media feeding frenzy, but didn’t plug the porous border. Now the frenzy is back, this time over dead children.

Just last week, an 8-year-old Guatemalan boy died in custody, the second child from that country to die on the American side in a month. The first was a 7-year-old girl, and both children had been held with a parent after crossing illegally.

The horrible deaths set off predictable partisan fireworks, with Democrats demanding an investigation and many on the left accusing the administration of heartlessness despite frantic medical efforts to save the children.

The White House responded quickly by dispatching Homeland Secretary Kirstjen Nielsen to the border and promising better and expanded health screenings.

Color me skeptical that either an investigation or enhanced care will ultimately improve border security or migrant health. The reality is that the sheer volume of illegal crossers, combined with advantages the law gives those traveling with children, means the expansion of benefits will almost instantly be swamped by tens of thousands of new arrivals.

Moreover, great danger is inherent in the long trek, especially for young children, some of whom may have pre-existing health conditions. It is not callous to say that it is unrealistic and unfair to make American border officials — and taxpayers — responsible for children whose parents are so irresponsible. Nor is it compassion to encourage Central America’s poor to believe that getting to the border is akin to reaching the promised land.

As reader Mary Churchman put it: “If I set off on foot across this country with a 7-year-old child and dragged said child 2,500 miles, I would be charged with child abuse. Further, if the child died at the end of the journey, I would be charged with murder.

“Yet when a migrant child dies on US soil, our officials face threats of losing their jobs, thereby endangering the welfare of their own families, all because someone from a country thousands of miles away felt he had the right to enter my country.”

Churchman doesn’t say so, but we can assume she supports Trump’s push for an expanded wall. So do I.

The government shutdown over the funding impasse between the president and congressional Democrats is spurring endless commentary about whether Trump will be punished politically. A hostile media is trying to make certain he is, despite the fact that Senate Dems are blocking passage of the House bill that contains $5 billion for the wall.

Yet because of the dead children, emotions are again threatening to drown out the substance of the dispute. The result is that there is precious little focus on the role a wall could play in stemming the tide of suffering humanity washing up on America’s southern border.

In fact, had there been a wall and true border security, there is a reasonable chance the parents of the two dead Guatemalan children would not have attempted the hazardous trek.

Walls, after all, are not just barriers. They are also deterrents that can dissuade would-be migrants from even attempting to reach the US.

Conversely, it is well documented that the openness of vast stretches of our border invites thousands of people fleeing their Central American homelands. Throw in the open-border activists teaching migrants how to apply for asylum, and court rulings that allow illegal crossers to stay pending hearings, and the incentives for making the journey are obvious.

And don’t forget the hellish crime and violence engulfing Honduras, El Salvador and Guatemala. Those nations make up what is called the Northern Triangle, the region with the world’s highest homicide rates.

It is, of course, a reflection of Trump’s helter-skelter style that he decided to force a showdown over the wall in an 11th-hour effort to fulfill a campaign promise before Dems take over the House.

Nonetheless, the shutdown has exposed the hollow core of the Dems’ insistence that they support border security while opposing a wall.

Nancy Pelosi, the likely next speaker, has called the wall “immoral,” yet in a statement she vows to “fight for a strategic, robust national security policy, including strong and smart border security, and strong support for our service members and veterans.”

That’s not even mush. It’s a word salad meant to suggest toughness without offering a single specific example of what Dems would do to plug the border. She won’t admit it, but she has no plan except to further weaken the disastrous policies now in place.

On the other hand, after the first Guatemalan child’s death, Pelosi declared that America has “a moral responsibility to ensure all children are treated with decency and compassion.”

Does that include the children in Chicago and other cities falling victim to gunfire?

The contrast is sharp: Trump sees morality as putting Americans First, while Pelosi sees morality as offering a better welcome wagon for those who come illegally.

Build the wall because we have tried everything else.

De Blasio can go stick it

Sometimes it’s hard to know which is worse for the city: when Mayor de Blasio does nothing or when he has an idea. Take the case of his program for providing public boxes for junkies’ used hypodermic needles.

The Post reports that more than 59,000 used syringes were found in Bronx parks, some only feet away from the green boxes. Meanwhile, only 7,000 were actually deposited in the 44 boxes — or just 11 percent of the total number of needles.

Residents and workers say the boxes are worse than useless because they attract junkies to the parks and encourage them to shoot up there, which scares away other visitors.

The mayor’s response: He’ll hire more workers to clean up the needles.

Brilliant.

Please, Mayor Putz, go back to sleep and leave New York alone.

Crappy News Year

A friend writes that The New York Times has posted its ultimate anti-Trump headline: “Trump Imperils the Planet.” That recent editorial title perfectly captures the paper’s relentlessly radical views of the 45th president.

The Gray Lady is not alone in using extreme language to convey its hatred of Trump. With upwards of 90 percent of coverage of him by all media so negative that it borders on vicious, 2018 draws to a close the way it began. And 2018 was merely a continuation of 2017.

All of which gives me supreme confidence in my gloomy prediction for 2019: more of the same media bias against the president. Bet on it.

Feel free to wreak havoc

Disturbing fact of the week from The Wall Street Journal: “Twenty-three percent of defendants convicted of violent felonies in state courts are sentenced to no incarceration.”