Donald Trump, behind the curtain. Jim Young/REUTERS Roger Stone couldn't fly to New York.

Stone, the flashily dressed confidant for decades to Donald Trump, had injured his eye in a boxing match and underwent retinal-reattachment surgery. The doctors said he couldn't fly because of the cabin pressure.

So there he was in Miami on June 16, 2015. He watched his close friend descend down Trump Tower's iconic golden escalator and deliver the speech that would launch the biggest movement in modern American politics, as if he were pretty much anyone else that day. On television. On Fox News.

Stone has been close to Trump for more than three decades and remains a top ally to Trump despite having no role with his campaign. That day was the culmination of a multiyear effort — from the brief flirtations with presidential runs to the boardroom sessions in "The Apprentice" — to mold Trump into what he is trying to become Tuesday:

A president.

"So he's a phenomenon," Stone said in a recent interview with Business Insider. "He came to the race with a universally known persona, which is something he carefully cultivated through many, many years of understanding self-promotion and the promotion of his brand."

It's a "movement unlike anything we've ever seen" in modern American political history, Trump often says. And he's right. It is a movement built on shared and mostly silent feelings that have burst out into the open thanks to the musings of a brash billionaire.

It's built on racial politics and, on many levels, politics of yesterday. It's built on shared frustration, anxiety, and feelings of being left behind. But mostly, it's built on the candidate who finally brought it out. And for Trump, the bond has been reciprocated with a fierce loyalty to his most fervent supporters — many times to a fault.

Down the escalator he came. Christopher Gregory/Getty Images

'Some, I assume, are good people'

It took him almost 2,000 words to say it.

Trump had flirted with presidential runs in almost every cycle for more than two decades. It didn't seem like a sure thing until he said the words on June 16, the date of a "major announcement."

He descended the escalator inside Manhattan's Trump Tower. He rambled. He went off on tangents. Finally, he said it.

"So, ladies and gentlemen, I am officially running for president of the United States, and we are going to make our country great again," he said, those last five words becoming the rallying cry of his campaign.

Something he had said much earlier in his speech, though, would become a source of controversy for weeks.

"When Mexico sends its people, they're not sending their best — they're not sending you," Trump said. "They're sending people that have lots of problems, and they're bringing those problems with us. They're bringing drugs. They're bringing crime. They're rapists. And some, I assume, are good people."

Democrats condemned the mogul. Businesses severed their partnerships with him. And much of the Republican base rallied around him.

"As soon as it became clear that he wasn't backing down from the Mexican rapists speech," Ann Coulter, the conservative best-selling author and prominent Trump supporter, said of when she realized the staying power of the Trump phenomenon. "I said he was the best GOP candidate two days later on Bill Maher's 'Real Time,' and the salt-of-the-earth audience hooted and sneered at me."

'He was a joke'

Tim Miller was in a Target in Miami, attempting to buy supplies for his new apartment there. But he became sidetracked when a phone call with a cable-news anchor devolved into a shouting match about Donald Trump.

Miller, the former communications director to the campaign of Jeb Bush, was miffed about a Trump interview sucking up airtime during Bush's first day of campaigning in New Hampshire.

"I got into a couple of heated arguments with cable bigwigs over their coverage of Trump, and I will admit a big part of my argument to them was that he was a joke and was not likely to even stay in the race in the end," Miller said. "In fairness, he had flirted with running and pulled out a few times before, so I don't think that was unwarranted."

Trump launched his campaign one day after Bush, who had spent six months crisscrossing the country and testing the boundaries of campaign-finance law by building a near-insurmountable war chest for what would become his campaign's super PAC.

The Bush campaign could hardly have expected the opportunity it received in the first week of campaigning, however, after Trump's comments about Mexican immigrants. Bush had been scheduled to do a bilingual interview with ABC's David Muir two days after launch — one day after Trump.

"I also mistakenly believed the contrast that week with Jeb doing a bilingual first network interview with David Muir and Trump calling Mexicans rapists would accrue to our benefit," Miller said.

"Clearly it did not."

Instead, Trump sucked air out of Bush's liftoff, and he became the story. Bush quickly became perfect fodder for Trump, who, in one of his first instances of branding an opponent with a devastating nickname, labeled him "low energy" and the exact opposite of the kind of president the US should elect.

On June 16, 2015, Bush was on top of national Republican primary polls. Trump languished in the bottom half of the outsize field, registering 3.6% support in a RealClearPolitics average of recent surveys. One month later — July 19 — Trump was at 16.8%, leading the pack.

He never looked back.

'Lightning in a bottle'

The first voter whom Chris Arnade heard mention Donald Trump's name didn't want his picture taken. No name, either.

Arnade, a photographer who has extensively chronicled America's addiction crisis, was on assignment for The Atlantic days after Trump launched his presidential campaign.

The man was a mechanic in upstate New York, areas of which have fallen by the wayside in an ever-globalizing American economy. The man was embarrassed about it — the press was mocking Trump's candidacy and calling him a racist — but he kind of liked Trump.

That week, crisscrossing through the US as part of a trip that would put a toll of 18,000 miles on his car, Arnade found a common theme. Pretty much everyone he talked to who was white was a fan of Donald Trump.

"This is serious," he recalled thinking. "This guy's putting lightning in a bottle. And what that lightning was and why took me a little longer."

"It was just, someone finally f---ing — thank God someone's finally being blunt about it," Arnade added of the common feeling among Trump supporters. "'We've been saying this for a long time, and people look at us like we're freaks.' It's brash, it's loud, it's crude. It's a bit like a group of pirates."

Trump's slogan, "Make America Great Again," evoked the themes they had felt in their own lives. Republican pollster Frank Luntz, in a conversation with Business Insider in August 2015, called the expression by far the most efficient of any candidate on either side of the aisle.

"As angry as people are these days, you have to give them a mission or vision of something better if you want them to follow you," Luntz said then.

And so they followed the candidate who said the things they wanted to be said — much of it shocking to a political and media establishment they despised. There was the comment about Mexican immigrants. The dig at Sen. John McCain's status as a war hero. The proposed ban on Muslims entering the country.

Then they brushed off the countless insulting, offensive comments about targets as varied as Fox News hosts and a physically disabled New York Times journalist.

Arnade tells the example of Lewiston, Maine, a city that sits in Maine's 2nd congressional district, which may give Trump a surprise electoral vote. Its unemployment rate is 3.7%, but it is not properly measured by economic statistics. Years of economic decline in the mill town have led to a restructuring as the mills have gone away.

A few years ago, Somali refugees began settling in the town, looking for areas with affordable housing, low crime, and good schools. The former community has become distrustful of the current, longing for days when the mills provided not only jobs but a sense of community.

"A community loses jobs. A very different group of people comes in and is given rights," Arnade said. "History is filled with places where if you have inequality, people blame scapegoats."

Donald Trump. Thomson Reuters

'Double bind'

The Republican politicians, they fled in droves.

They had stuck by his side in late May, when he was in the midst of attacking a federal judge's Mexican heritage. They had powered through in July, when he attacked a Gold Star family (a fight he never truly relinquished).

This one, though, was a bridge too far. Trump had been caught on tape boasting about how his fame gave him permission to grope women and kiss them without their consent. There were the swing-state prospective members of Congress. Then there were the three-term members of Congress from deep-red Alabama who disavowed, unendorsed, even called on Donald Trump to drop out of the race.

He did not.

He followed the same script he has through each controversy — he dug in, even as no fewer than a dozen women came forward to accuse him of unwanted sexual advances. And his supporters, they dug in with him.

"The GOP electorate overwhelmingly wanted politicians to back Trump, so anyone who demonstrated the courage to stand up to him saw their popularity drop," said Miller, the former Bush campaign communications director.

And then a funny thing happened. He came back to life, with the help of the final October surprise: the FBI's reactivation of an investigation of Hillary Clinton's emails. Republicans, realizing their renewed sense of distaste for Clinton, rallied back around him, polls showed. He climbed back to a position that provides him a few narrow paths to victory.

Trump has frustrated some of his closest allies with his campaign missteps. His campaign has taken away his access to his Twitter account, according to people close to him. They don't like how he has done almost no Spanish-language media and looks set to lose by near-historic margins among Latino voters. They resent his message to minority communities ("What the hell do you have to lose?!") when it could be much more uplifting.

His rise has broader ramifications for the Republican Party, now at a crossroads. Just four short years ago, the party released an "autopsy report" on Mitt Romney's loss. The GOP, it said, had become "out of touch" and filled with "stuffy old men." It was "talking to itself" rather than reaching out to new constituencies. The perception was, simply, that it did not "care about people."

That will continue.

"The party is in a double bind that is going to be challenging to escape. The more we appeal to the core primary voter and core Trump voter with a hardline message on immigration and extreme rhetoric, the more we turn off the general electorate," Miller said. "Meanwhile, the candidates who tried to have a more welcoming, optimistic, inclusive message all were largely rejected by the primary electorate."

But here we are. Eighteen months later, Donald Trump still has the Republican Party by a string. He is their past. Their present.

And, win or lose, their future.

As Stone put it: "It'll be a great book. It's an epic drama."