Slumlord Donald

President Trump made gutting vital domestic spending programs a certainty when he committed last month to increase military spending by tens of billions of dollars, paid for by slashing deeply elsewhere in the upcoming federal budget. Any dim hope that he intends to spare the metropolis he hails from is now put to rest by a draft spending plan for the U.S. Department of Housing and Urban Development that found its way to the Washington Post.

Or to put it in Daily News-ese, TRUMP TO CITIES: DROP DEAD. Don’t mess with us, Donald. Under Trump and department Secretary Ben Carson, HUD prepares to more than decimate its budget by 14%, thrashing vital housing and community development programs.

Trump’s own New York City and its Housing Authority, accounting for 1 in every 5 dollars the federal government spends to support public housing, could lose more than $100 million in subsidies for that purpose alone, plus thousands of rent aid vouchers.

Which can be expected to directly translate into more moldy apartments, leaky roofs, broken elevators and darkened stairwells in the projects that are home to nearly a half-million New Yorkers.

Also on the chopping block: HUD’s Community Development Block Grant and HOME programs, which together will this year grant more than $200 million to the city for affordable housing development and preservation, housing code inspectors, homeless shelters, ramps for people with disabilities, supportive housing for the mentally ill and drug-addicted, homelessness prevention, foreclosure recovery, senior centers, day care, blight clearance and more.

Without this funding, completion of Mayor de Blasio’s dream of building or preserving 200,000 affordable apartments could well implode.

HUD recommends injecting replacement community development funds into Trump’s expected national infrastructure-building plan. We’d be delighted — and shocked — to see dollars for code inspectors and apartments for the mentally ill homeless in the President’s steel-and-asphalt road map.

It’s also not too much to ask HUD and Congress to finally push through long-delayed policy changes to how public housing is run that could make their budget cuts something other than mere sadism — for instance, making widely available the successful Rental Assistance Demonstration program, which lets cities use private borrowing to pay for public housing renovation.

With many NYCHA buildings already crumbling for want of sufficient government investment, and authority Chairwoman Shola Olatoye staving off budget collapse following years of diminishing federal funds, the sharp budget shocks proposed would send public housing — and not just in New York City — over a financial cliff.

Congress cannot let such a savage attack stand, even if Trump and Carson do.

For his part, de Blasio must do much more than bemoan the federal fiscal assault while shaking his fist yet again at Trump Tower.

He must now, even before the federal budget is done, and yes, even in this mayoral election year, detail a dollar-by-dollar game plan for how a city that has survived so much adversity will retrench and weather these cruelest cuts.

Don’t just advocate, Mr. Mayor. Manage. It’s your job.