If Donald Trump becomes the next president of the United States – which is looking slightly more likely – he will, so to speak, hit the wall.

Yes, he will hit his wall: the beautiful, technological marvel he plans to build along the southern border to keep out people he thinks are going to harm the United States.

Yet the first thing he might have to do is to send recruiters into Mexico and beyond to find craftsmen to build his wall.

Mexico might not pay for the Trump wall, but Mexicans most certainly will build it. The reason: there is a critical labor shortage in the United States of skilled craftsmen and women.

There are still way too many unskilled people arguing over what the minimum wage should be for selling a hamburger and far too few who can swing a hammer, use a spirit level, lay a brick, connect a sewer line or wire a building.

These people, these yeomen in 21st-Century society, are in critically short supply. Known as the “crafts,” they are the people who build our bridges, water systems, power plants, submarines and other military materiel, and restore power after a storm.

Whether you are trying to build a new suburban house, a ship or a road, you need the crafts: people who work with tools and their bodies. Their brains, too, for it is not brainless work. Do not ever think that  it is. The glass sheathing on those super tall, super skinny buildings in New York would not have gotten there, or stayed there, without people with brainpower.

The crafts shortage is not hypothetical: it is affecting new home construction and big projects, like new nuclear plants in South Carolina and Georgia. 

Utilities have special programs to train people to climb poles, string lines, and become first responders after severe storms. These are secure jobs with benefits and retirement packages. Nice work if you can get it, and you can get it if you get round your local utility hiring office.

The political response to the crafts shortage is predictable. There are demands for trade schools, for special courses, for subsidized apprenticeships. As usual, money will be requested. It is not a money problem. It is a human-resource allocation problem.

There is simply too much social, I repeat, social value attached to a university education -- an education that often wastes time, while the students learn what they should have learned in high school.

A degree from one of the second- and third-tier universities is increasingly of little value in getting work. How many political scientists, communications executives, and marketing gurus does society need? An arts degree qualifies its recipient in today’s market to be an Uber driver or such.

Societal pressure says if you do not have a university degree, you are inferior. Everyone without a degree butts up against the mortar-board ceiling at some time.

Yet much of what passes for education is, in fact, the ability to pass tests. Test-passers move up the system and seek other test-passers to keep the game going.

But we are happy to entrust air traffic control, policing, ship piloting, EMT response and other life-saving jobs to people with only high school educations. All those welds on ships, nuclear plants and bridges, are the work of high school graduates and dropouts.

I am happy to report that one of my wife’s nephews has told his mother, an Ivy Leaguer no less, that rather than going through the warehouse-as-education system, he is going to be a welder. I hope he works on worthwhile things, like a bridge or a submarine, not on Trump’s silly wall.

Let the Mexicans have that as their jobs program -- which we will pay for. Believe me.

Llewellyn King is executive producer and host of White House Chronicle, on PBS. His e-mail is llewellynking1@gmail.com.  He is also a Rhode Island- and Washington,D.C.-based publisher, columnist and international business consultant.