Two images bookend the most remarkable political contest of modern times. In the first, Donald Trump rides an escalator down to the lobby of Trump Tower to announce his fanciful campaign for president. In the second, Election Night maps on television screens flash red as 30 states fall like dominoes into Trump’s column.

Just 17 months elapsed between those unforgettable moments, yet that span stands as an epoch unto itself in the history of America. We were eyewitnesses to a revolution, a rising up of people who felt shunned, betrayed and left behind. They called themselves “deplorables and irredeemables,” turning Hillary Clinton’s slurs into a rallying cry as they threw off the yoke of the old political order and trusted the nation to a true outsider.

Hallelujah for an American tonic and a necessary course correction.

Donald John Trump is the most unlikely revolutionary ever to stalk western civilization. He built buildings and a personal fortune, then nearly lost it all before rising again by making his name synonymous with wealth and success.

His life was his brand and it was more grandiloquent than any opera. He was a playboy, a serial seducer and the incarnation of a new and sometimes vulgar Gilded Age.

His marriages, divorces and high jinks were catnip for newshounds. He was tailor-made for TV and became a household name with his signature line, “You’re fired!”

He was a rich celebrity who had it all, but it wasn’t enough. He had the chutzpah to dream he could spin his star power into political gold.

For his daring, he was mocked and made the butt of endless jokes, especially about his hair. Perhaps their laughter blinded the savants, for they missed the birth of a phenomenon. A clue that foreshadowed the ultimate outcome was hiding in plain sight, yet precious few saw it.

From the moment Trump stepped off that escalator in June of 2015 to join the race, producers at television news programs realized that the more they turned their cameras on him, the more viewers they got.

So that’s what they did, and in a flash, Trump’s rallies were bursting at the seams as thousands showed up when other candidates were lucky to draw hundreds.

His slogan, Make America Great Again, was so in-your-face that there was no mistaking its meaning.

The scoffers, including nearly every major news organization and all the pooh-bahs of Washington, consoled themselves by thinking it was a bread-and-circus act, that people were turning out just to gawk at a rich buffoon.

They reassured each other that when the voting started, the unwashed rabble would come to their senses and Trump would crash and burn like a cheap hot-air balloon. Then they, the all-knowing elite, would go about their business of anointing a respectable Republican who would dutifully lose the general election to Clinton. That’s the way the world worked. *

That mistake would be forgivable if it were a one-off. But it was just the start of the establishment’s failure to understand what was happening in the huge swath of America that stretched beyond the Beltway and between the urbanized coasts.

To this day, most of the professional scoffers still write off Trump’s stunning upset as the revenge of an angry white working class stewing in hate. Journalists who bother to sojourn to red-state hinterlands approach his supporters as if they are visiting the zoo.

Trump knew his audience from the start. Just as his genius for selling his brand made him rich, his genius for reading the electorate made him president. There was a desperate hunger among millions upon millions of Americans for a bold leader and he aimed to feed it.

He was all brass bands and bare knuckles and exactly what Republicans and many independents wanted. He didn’t take crap from anyone and said what those voters were thinking about jobs, trade, immigration and so much more.

His slogan, Make America Great Again, was so in-your-face that there was no mistaking its meaning. It was nationalist and populist, and the fact that those ideas offended the tender sensibilities of the political and media elite was a bonus. Trump’s no-bulls–t approach struck a deep chord in the hearts of Americans who felt abandoned by both political parties and their government.

Their patience and their bank accounts were exhausted. From the horrors of 9/11 to the quagmire in Iraq to the economic collapse in 2008, George W. Bush’s presidency was a demoralizing slog. Then came eight years of Barack Obama’s lectures, apology tours and liberal overreach. As ObamaCare and other stifling impositions slammed the door on the American Dream, many citizens were equally furious at Republicans in Congress for failing to fight back.

None of them was fooled by happy-talk statistics about jobs when the economy they lived in still dragged along the bottom. Throw in the nightmares spawned by the medieval butchery of the Islamic State, including a spate of homeland slaughters, and a huge slice of the electorate was primed to put someone very, very different in the Oval Office. *

Alas, smooth sailing is not in Trump’s DNA. He had — and has — a knack for going too far, and his embrace of the claim that Obama was born in Africa, and thus ineligible to be president, threatened to derail him until he formally backed down. That misbegotten venture remains an open wound to many African-Americans who see it as a racial attack on the first black president.

But it is also true that Trump is “an equal-opportunity offender,” as his daughter Ivanka once said. In that and other ways, he evokes memories of another pot-stirring New Yorker, the late, great Ed Koch. In fact, Koch might have been thinking of Trump as well as himself when he wrote, “I’m not the type to get ulcers, I give them.”

Trump’s gift for the zinger insult — “Little Marco” and “Lyin’ Ted” — found its ripest target in Jeb Bush. “Low energy” fit like a glove, and the former front-runner wilted.

Yet Trump looked like he had another gift, too: an ability to snatch defeat from the jaws of victory. Again and again, he would build momentum, only to throw a banana peel in his way, or have one surface from the past. The tape where he boasted that he would walk up to women and “grab them by the pu–y” nearly sank him because there was no denying his own words.

That was the low point of a pattern that would play out right up to Election Day. Indeed, it hasn’t fully stopped yet.

The transition, for all his great success in jawboning Carrier Corp. and carmakers to build their products in the USA instead of Mexico, is also being defined by angry Tweet storms as Trump punches down the likes of actress Meryl Streep. To the extent that they mean anything, polls show him losing ground during a period when presidents-elect mostly expand their popularity.

It’s the Trump way and we’d better get used to it. He is who he is, authentic to a fault.

But his critics, especially those whose heads are exploding over his election, should also remember this: His upside is enormous. His fierce determination to succeed now stands to benefit the nation.

Trump, though he certainly can be headstrong, is also willing to change course when he has to. And don’t forget his incredible stamina, which helped him beat Hillary Clinton by outworking her down the stretch.

Most important, the areas of his signature focus — unchecked illegal immigration, a decline of good-paying manufacturing jobs and a depleted military — are fundamental to a national revival. They are daily obstacles to our fellow Americans, and our security and must be fixed if our democracy is to endure and prosper.

Trump was tested by the fire of a brutal campaign and was on the receiving end of an unprecedented barrage. It was one thing for the slings and arrows to come from his opponent and the White House, quite another for the media to conspire against him. The powerful confederacy against him made his triumph all the more amazing.

Still, it is worth repeating that while he is president No. 45, he is the first to have had neither government nor military experience. That seems risky and it is a virtual certainty that he will be tested early and often, both at home and abroad.

Already, the boycott of his inauguration by sour-grapes Democrats breaks new ground in disrespect and dangerously sows seeds of disunion. Who knows what challenges China, Iran, Russia and the Islamic State will present.

Besides, it’s not as if Barack Obama leaves Washington and the world in splendid shape, so there’s no shortage of existing difficulties. History, if it’s honest, cannot treat Obama kindly.

Now it’s time to look forward. Donald Trump is the new sheriff in town and, like Sinatra, he did it his way. Say a prayer for him and the exceptional nation he leads.