The possibility of Donald Trump assuming the highest office in the land should terrify every clear-thinking American in the United States. It doesn’t. That confounds many on the right, left, and middle of the political spectrum.

The latest polls suggest the gap between Democratic presidential nominee Hillary Clinton and her GOP rival has tightened. Ordinarily, that might not raise an eyebrow at this juncture in the presidential campaign.

But Mr. Trump is where he is now because he got a free pass from the mainstream media way back when. We figured he was a joke, a faux populist on an ego-driven publicity stunt.

We considered The Donald little more than an entertaining break in a sea of bland. Boy, were we wrong.

The primary season performer ascended to presidential nominee because his act hit home with people starved for attention. Finally, poor, working class whites had a platform.

Their erratic spokesman gives voice to the concerns of rednecks, white trash, hillbillies. That’s from a man who wrote a memoir about his hillbilly, white trash heritage and the dysfunctional clan he endured as a child of Appalachia.

J. D. Vance split his time between Jackson, Ky., and Middletown, Ohio. He enlisted in the Marines, his saving grace, after high school. Eventually, he graduated from not only Ohio State University but Yale Law School.

Today, the 32-year-old is married and a principal in a Silicon Valley investment firm. But he never forgot where he came from in the holler.

He was raised by “dirt poor” grandparents. Papaw drank too much and the beloved, ever-profane Mamaw almost killed him. They clawed their way to middle class.

They also kept their grandson on the straight and narrow when his mother, addiction, and multiple dads could have derailed him. The Vance book, Hillbilly Elegy, is an intimate romp through broken lives, dreams, and culture.

It is a must-read to understand the demographic Mr. Trump tapped into for steady support. Nothing the capricious Donald says or does shakes the belief of his hillbilly faithful.

In a phone call from San Francisco, Mr. Vance explained why.

● He’s relatable.

“Think of Mitt Romney or Hillary Clinton or Barack Obama, the elites of either political party. The way they speak, the way they communicate is filtered, like it was approved by a political consultant. Donald Trump sings a different tune, more off the top, not politically correct, sometimes offensive. If you grow up feeling that everybody you see on TV talking about politics is nothing like you, they’re not relatable.”

● He sees them.

“A lot of these voters [who grew up like J.D. did] have felt invisible for a very long time. They feel like the political elites don’t even care about the problems in their lives, whether economic or noneconomic stuff like epidemic addiction, family breakdown, a general sense of pessimism about the future.”

● He knows how to wheel and deal.

“There is a sense that look, this guy knows how to play the game and clearly, we are struggling because we don’t know how to play the games. So maybe they [the white working class] don’t hold his billionaire status against him. Maybe they actually take it as a positive because it adds to his higher persona of being a turn-around artist.”

● He gives voice to their anger.

“You grow up in an area, maybe it’s rural, maybe it’s suburban. You don’t make a ton of money. You’re worried about your job. You’re very angry at a number of people. Maybe you watch them on TV. You yell at the TV or you just sit there quietly and stew. You never had someone say what you wanted to say to the elites.”

● He fans their fear of different.

“Racism is definitely a part of the Trump phenomenon. And I think to his great discredit, Trump has not disavowed the David Dukes of the world as strongly as he should. But there’s another group [migrants from Appalachia] that are not fundamentally hateful people. Maybe they have some racial anxiety. They’re a bit unsure of people who are different from them, in part because they don’t spend time around them.”

Mr. Vance, a Republican, says one reason he is so against Donald Trump is because he’s encouraging his base — the people and community known by the author — to think of their fellow citizens “as scapegoats for all of their problems. He’s taking that significant portion of the white working class poor, who are not explicitly racist, and pulling them in a more racist direction.”

There’s more. Lots. And it should terrify everyone about the prospects of a President Trump.

Contact Blade columnist Marilou Johanek at: mjohanek@theblade.com

First Published September 10, 2016, 4:00 a.m.