America’s political experts got it wrong in 2016 — not because they took too few polls, but because they made the false assumption that American elections are immune to societal change.

They are, in large part, still getting things wrong, not only by failing to understand a new group of voters who put President Donald Trump in the White House but also by ignoring why they voted the way they did.

When explaining the Trump voter, the media usually offers portraits of isolated, uneducated, working-class rubes who are driven by anger, race and nationalism. To the experts and those who didn’t support Trump, it’s hard for them to see it any other way.

And while the media obsesses over the future demise of the president, they aren’t pausing to consider the strength and durability of the coalition that swept him into office.

They aren’t asking why people in the Rust Belt counties who voted for former President Barack Obama twice suddenly switched to Trump.

But they should. Because Trump was not the cause of this movement, he was the result of it. In order to fully appreciate his rise to the White House, you need focus on the people who put him there.

My new book, “The Great Revolt: Inside the Populist Coalition Reshaping American Politics” (Crown Forum), co-written by Brad Todd, is a road trip into the lives of Rust Belt voters who switched their states’ allegiances in the presidential elections from 2012 to 2016.

On the back roads and side streets of places like Erie, Pa., and Kenosha, Wis., emerge blue-collar optimists, evangelical pragmatists and suburban vacillators who turned the dials just enough to shock the body politic, leading to an emerging populist-conservative alliance that wrecked the old partisan framework.

Far from a fluke, the 2016 election was a product of the tectonic plate-grinding of our society — a backlash against globalism, secularism and coastal elitism. An August 2017 survey of 2,000 self-reporting Trump voters in the Rust Belt, commissioned by me and my co-author, revealed their motivations, priorities and decision making, and reinforced what we had found in our interviews.

In “The Great Revolt,” out Tuesday, we pinpoint and describe several archetypes of the new Trump voter, many of whom broke ranks to back him. Those hoping to predict what comes next in American life should study them — because the ballot box likely won’t be their last venue for change.

HIDDEN IN PLAIN SIGHT

JEFFERSON, Ohio — When you walk into the Legally Sweet Bakery on Chestnut Street you can barely see Bonnie Smith standing behind the display cases filled with sugar cookies, tea cakes, cream wafers, brownies and mini tarts.

But don’t let her diminutive size fool you. At 63, Smith is a powerhouse. After working her way up from a cook’s job to the role of deputy sheriff at the Ashtabula County Sheriff Department, she is now in her second career as a small business owner.

It is 9 a.m. on a Tuesday, and she has already been up 8 ½ hours baking delicacies to fill her cozy shop.

For years, Smith’s politics reflected her community. She was raised a Democrat, her parents were Democrats, her husband was a Democrat, she worked for the Democrats. She even voted for Bernie Sanders in the presidential primary in March 2016.

And then, suddenly, “I woke up one morning and said ‘I had had enough.’”

Smith says her dissatisfaction grew as she looked around her community. The main-street business district where her bakery is located was sprinkled with closed storefronts. The opioid crisis had ravaged the area, and every news story was about job cuts instead of job creation.

“I am kind of that voter that was hiding in plain sight that no one saw coming. I was right here all along. I’ve seen the job losses here, the rising crime, the mess and heroin problem, society essentially losing hope. Something just gave in within me,” she said.

To her surprise, her husband echoed her sentiments. They both voted for Trump.

Smith’s journey to that point was not an evolution, it was a revelation. And many others in Ashtabula County, Ohio, experienced the same eureka moment: The exact county that gave Barack Obama a 55 percent majority of its vote twice, swung a remarkable 31 points to give Trump a victory over Clinton by a margin of 57 percent to 38 percent.

ROUGH REBOUNDERS

ERIE, Pa. — Dave Millet bears a striking a resemblance to Kenny Rogers as he stands outside the Ugly Tuna Tavern on Peninsula Drive in this northeastern Pennsylvania industrial town.

It’s a resemblance he’s taken advantage of for the past 30 years as an impersonator at local bars and casinos in the region. “It’s fun and it’s extra income. Here, let me show you,” he says as he stands up to sing:

“You got to know when to hold ’em,

Know when to fold ’em,

Know when to walk away,

And know when to run.”

A group of young people cheer him on as they walk inside the tavern.

Millet (inset) hasn’t had an easy life. He’s been up, he’s been down, he’s been up again only to be struck down by illness. Now he’s back up again.

Never once has he ever given up.

“You can’t give up. You reinvent yourself, you make bank, you find a way. I’ve lost plenty of jobs and I’ve earned plenty of jobs. You just keep climbing back up,” he says.

Unconventional candidates attract voters for unconventional reasons, and the way Americans pick presidential candidates can be as emotional as any consumer behavior.

One group uniquely attracted to Donald Trump, regardless of their politics, was voters that experienced setbacks in life and saw the same kind of vulnerability and recovery in Trump they had experienced themselves.

For this group, which I’ve named the Rough Rebounders, Trump’s appeal was inextricable from his foibles, be it bankruptcies or family ruptures or tragic mistakes.

In his underdog status, they found a candidate with whom they identified. Trump’s constant positioning of his candidacy as counter to the Republican party’s desires, and even his unvarnished struggle with factual accuracy on the campaign trail, affirmed him as the candidate of last chances and won him a legion of loyalists among Americans facing their own second, or even last, chance in life.

“Yes, I’d absolutely vote for Donald Trump again,” Millet, 68, says. “But here again, like Reagan, I’m gonna keep his feet to the fire. Long as he’s trying, as long as he makes sure he has our back, well then he has my support.”

CHRISTIAN SOLDIERS

BRISTOL, Wis. — Julie Bayles did not decide she would vote for Donald Trump until she walked into the voting booth on Nov. 8, 2016.

The 44-year-old mother of seven took issue with Trump’s coarse language and boorish behavior on the campaign trail and found both incompatible with the commands of her own Christian faith.

“It was the hardest decision I think I’ve had to make as an adult in any voting process,” Bayles says.

“It was so difficult. And I think the reason it was so difficult is because I don’t take it lightly. This is important. This is our country. This is my seven children’s future.”

Bayles’ evolution to Trump voter demonstrates how the president exceeded expectations with evangelical Christians and conservative Catholics.

How did a thrice-married, Playmate-courting, areligious New York billionaire become the leader of an evangelical political crusade? He punched back. And he offered a transaction: In exchange for Christian conservatives’ support, he vowed to defeat the enemies of religious liberty. Ultimately, they saw him as a warrior for religious freedom.

Bayles and her husband Donnie — along with two of their adult children — could easily have stayed home on Election Day when faced with their two choices. Instead, they were part of a political tipping point in Wisconsin, a state in which 22 percent of the adult population is affiliated with an evangelical protestant church and 71 percent overall identify as Christian.

The alliance between the billionaire and the believers, however transactional, has persisted well into Trump’s presidency.

“Funny, all of that anxiety, all of that praying,” Bayles says, “and it turns out I like him now much more than I did when I voted for him.”

RED BLOODED AND BLUE COLLARED

WILKES-BARRE, Pa. — Ed Harry is sitting in the booth at the back end of D’s Diner in Plains Township, Luzerne County. Up front, the place is filled with customers at a chrome lunch counter as waitresses busily fill coffee cups, take orders and greet regulars with a familiar, “The usual?”

For most of his life Harry (inset) has done two things: voted Democrat and lead union workers.

A Vietnam War veteran, he became a Democrat as a teenager and found his calling in the unions when he took a job as a custodian in a state mental institution.

Harry helped campaign to turn public sector facilities into union facilities. “Turns out I was good at persuasion,” he deadpans.

He swiftly moved up the ranks, becoming a contract negotiator. When he retired after 25 years, he was president of the Wilkes-Barre Labor Council.

But, he says, when the establishment Democrats stopped caring about his people, he stopped caring about them.

Many working-class voters like Harry, 71, have been portrayed as anxious, frustrated, angry and desperate.

But my survey revealed a more complicated picture. The archetypal red-blooded, blue-collared Trump voter has worked an hourly-wage or physical-labor job after the age of 21 and experienced a job loss personally or in their immediate family in the last seven years. But a full 84 percent were actually optimistic about their future career path or financial situation, regardless of how they felt about their community’s prospects as a whole.

This inherent optimism is a key nuance missed by most analysts. It’s a sentiment that perfectly matched Trump’s positive, forward-looking slogan: “Make America Great Again.”

Harry felt that optimism.

“My party, the party that was supposed to be the party of the working guy, the guy I stood up for and worked for all of my career, was no longer part of this new ascending Democratic coalition. Blue-collar America essentially had the door shut in its face,” Harry says.

GIRL GUN POWER

KENOSHA, Wis. — Amy Maurer is a very striking woman, her blond hair cut short in the kind of dramatic fashion you’d see in the pages of Vogue or on a Paris runway.

Sitting in the conference room of TG3 Electronics, Chief Financial Officer Maurer (inset) is both in command and at ease, surrounded by the keyboards her company manufactures.

Maurer, 43, is the married, educated, suburban mom whom experts missed in the 2016 election — and still don’t get today. As a gun owner and strong defender of the Second Amendment, she based her vote entirely on the Supreme Court vacancy and who would fill it.

The Clinton campaign tried hard to win over voters like Maurer with ads highlighting Trump’s most misogynistic remarks, casting him as an unhinged troglodyte no self-respecting woman could support.

“They believed, I think, that the social pressure from either friends or professional peers would be too much. That we would cave because of his behavior. Well, they misunderstood where the emphasis of our vote was. They thought, ‘Feminist, right? Successful, kids in the home, married, college-educated . . . Oh, they cannot vote for Trump, they just cannot.’” She smiles broadly. “They were wrong.”

Women were the group most likely to bail on Trump after it was revealed — one month before the election — that he had crudely boasted of sexual exploits on the “Access Hollywood” tape.

Which is why the issue of gun ownership among women was critical. According to my survey, female Rust Belt Trump voters under the age of 45 are the demographic most likely to agree with the idea that every American has a fundamental right to self-defense.

“Got a couple in my office,” Maurer says of her firearms. “It’s smart, it’s empowering, it reminds me I am in charge of taking care of myself and my family at all times. I actually conceal carry because where I work, well, it’s a dangerous area.

“One of the things I think Democrats did not understand about women and guns is that empowerment that a gun gives you.”