(CNN) On the eve of the first Super Tuesday earlier this month, the siren call went out to Republican donors. Donald Trump was barreling toward the Republican nomination, and the chance to stop him was slipping away.

Throughout 2015, many top-flight Republican donors had stayed on the sidelines, waiting for a clear establishment front-runner to emerge. Then the unthinkable happened: Trump stepped into the void and began slaying his rivals one by one. None of them could figure out how to stop him.

The incredible momentum of his campaign stunned America and shocked the Republican establishment. Not only did the political world underestimate Trump's electoral strength; for months they belittled his candidacy with all its theatrics as a joke and failed to heed the signs of seismic change.

During a long summer and fall of denial as Trump consistently dominated the polls , even the savviest of Republican operatives insisted that he would never stay in the race. Few GOP donors were even thinking about the need for a plan to defeat him. Moreover, each candidate was focused on their own campaign and felt no sense of obligation to risk their chances by trying to stop him.

The belated call to halt his march to the Republican nomination happened hours before Trump started rolling toward massive victories in Super Tuesday states — building what looked like an almost insurmountable lead in the delegate count. But Paul Singer, a billionaire who is one of the GOP's leading bundlers, told fellow donors it was the moment to strike.

"He is not Superman" who can only be destroyed "by kryptonite," Singer said, according to several sources who heard the call and provided previously undisclosed details to CNN.

the first top donors to get behind Singer and members of the Ricketts family — amongthe first top donors to get behind the anti-Trump effort — believed the "real" Donald Trump had not been unmasked to the American public. They had to make an impact by March 15 to unravel a brand Trump had been building for decades, but they felt the facts were on their side.

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Joining Singer's plea for an unrelenting assault portraying Trump as the self-serving foe of "the little guy" was Hewlett-Packard Chief Executive Meg Whitman. Trump, she said forcefully, was driving an agenda of "hate and intolerance" that demonstrated he was unfit to be president.

The previous week, Whitman and other top Republicans around the country had watched with alarm as New Jersey Gov. Chris Christie had endorsed Trump . They feared other establishment figures across the country would see Trump's powerful allure to voters and start falling in line behind him.

It was late, but it wasn't over, Whitman assured donors on the call. The fight for delegates could go on for months.

"We have a shot at turning this around," Whitman told them, appealing to their patriotism and telling them they had "a duty" to step up.

A brief question-and-answer session followed. One donor set the tone with his query: Where should he wire the money?

Trump's Super Tuesday #3

The anti-Trump donor call that day set in motion what would become the end-run at the real estate mogul to prevent him from steamrolling through the winner-take-all contests that started Tuesday night on Super Tuesday #3 with Ohio and Florida. This account of their uphill climb and the unpredictable trajectory of the 2016 campaign is based on interviews with more than two dozen strategists, campaign aides, donors and party operatives.

Trump's foes reasoned that if they could not defeat him outright, they wanted a split decision at the very least. They got a version of that Tuesday: a John Kasich win in Ohio and a nail-bitingly close contest between Trump and Ted Cruz in Missouri. Originally a Marco Rubio win in Florida had looked possible -- but Rubio ended his campaign Tuesday night after a humiliating defeat in his home state.

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Trump's dominance Tuesday was a far cry from the desired result of the anti-Trump forces. But they got just enough to keep the contest going with a narrow path toward depriving Trump of the delegates he needs and the specter of a contested convention.

Trump was defiant on Election Night: "Millions of people are coming in to vote," he said during his speech at his Mar-a-Lago estate, where he noted that he was turning out "brand new voters" to the polls. "It's just a different thing. We have a great opportunity."

Two nights earlier at his Boca Raton rally, a Trump organizer had encouraged the attendees to tweet about the event with the hashtag #StopTheRepublicanEstablishment. Trump arrived just after sunset in cinematic fashion, flying over the lakeside venue in his private helicopter as the theme music from the 1997 Harrison Ford movie "Air Force One" stirred the crowd.

It was a general election-sized crowd that stretched from the amphitheater stage all the way across the grassy lawn to the edge of the lake. Taking in the scene after the helicopter had touched down, Trump's campaign manager Corey Lewandowski warned of the backlash that a contested convention would unleash.

"It's a decision for the party elites," he said in an interview, standing in a suit behind the press tent as Trump fired up the Boca crowd from the stage. "They can destroy the party or they can unite behind the front-runner."

"Continue to underestimate Donald Trump at your peril," he warned them.

Kindling for Trump's rise

The kindling that ignited Trump's candidacy in 2016 began falling into place some eight years earlier as the presidency of George W. Bush wound down and the U.S. economy collapsed.

For many Americans, the underlying economic anxiety about the crash would never dissipate. Rank-and-file Republicans -- already frustrated by the huge deficits racked up by the Bush administration in Iraq and Afghanistan -- were inflamed by President Barack Obama's push for the stimulus bill and Obamacare.

That anger would manifest itself in the rise of the tea party in 2009 and 2010 -- and initially much of the political establishment would mistakenly describe Trump's crowds as just the latest iteration of that movement.

But interviews at Trump's rallies throughout the summer and fall suggested he was tapping into something that stretched far beyond the narrow ideological frame of the tea party voter. Not only were many of the people who flocked to his rallies new voters, they were highly motivated to turn out for him.

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He was harnessing a mood of seething anger at Washington that cut across typical party lines and economic stratas. He was channeling the grievances shared by many Americans who felt left behind by the slow-growth economy, juggling multiple jobs and worrying about paying their children's college tuition. He responded to the fear that rippled across the country after the terrorist attacks in Paris last year.

While critics ridiculed his speeches as incoherent demagoguery, he was successfully stoking the anger of conservative, blue-collar workers. He reshaped the entire 2016 dialogue with his compelling nationalist argument that illegal immigration and trade deals were part of an unfair system that was working against them. Offering little in the way of detailed policies, Trump promised to use his business savvy to straighten it out.

"There has been an audience in the Republican Party for the message that Donald Trump is delivering that simply has not been served at the decibel level that Trump could provide," said CNN senior political analyst Ron Brownstein. "He is anti-trade, anti-immigration, pro-entitlement and generally anti-elite. It's this idea that we are under siege from both domestic elites and foreign influences, and he's going to fight both of them. These are the forces that are causing you to lose control of your life, to feel you are being passed over in your own country, that your kids have no prospects."

There were antecedents for Trump's message in Pat Buchanan in 1996 and Rick Santorum in 2012. But, Brownstein noted, "they didn't have anything like the wattage or the intensity that Donald Trump has."

He also had a special brand of political magic that all of the other 2016 GOP candidates lacked. Part of that was his uncanny ability to dominate the 24-hour news cycle -- touching off explosive news stories with his provocative tweets and then driving the cycle with his interviews.

At a time when most candidates were limiting their exposure on cable, for example, Trump would pop up for telephone interviews on multiple morning shows.

"There is no one else in America who could have pulled this off -- that mix of celebrity, wealth, mastery of PR and political currency," said one Republican operative, who asked not to be named discussing internal party dynamics. "This is the unicorn of politics. No one ever thought it could happen."

Republican denial

In January of 2015, long before anyone imagined that Trump would get this close to the Republican nomination, the real estate mogul put out the call for political resumes and summoned operatives to his Fifth Avenue office in New York.

As Trump eyed Lewandowski, who would become his campaign manager, he skimmed through a list of the other strategists he'd interviewed, posing one key question: "Are you better than all these guys?"

"I believe I am," Lewandowski replied, according to two sources with knowledge of the conversation.

Photos: Donald Trump in the public eye Photos: Donald Trump in the public eye Business mogul Donald Trump announces his candidacy for the U.S. presidency at Trump Tower on Tuesday, June 16, 2015, in New York City. Hide Caption 1 of 21 Photos: Donald Trump in the public eye Donald Trump attends golf legend Jack Nicklaus' Congressional Gold Medal ceremony on March 24, 2015, in the U.S. Capitol Rotunda. Trump announced on March 18 that he had launched a presidential exploratory committee. Hide Caption 2 of 21 Photos: Donald Trump in the public eye Trump speaks to guests at the Iowa Freedom Summit on January 24, 2015, in Des Moines, Iowa. Hide Caption 3 of 21 Photos: Donald Trump in the public eye As chairman and president of the Trump Organization and the founder of Trump Entertainment Resorts, Trump speaks during day two of the Republican Leadership Conference on May 30, 2014, in New Orleans. Hide Caption 4 of 21 Photos: Donald Trump in the public eye Former U.S. vice presidential candidate and Alaska Gov. Sarah Palin and Trump walk toward a limousine after leaving Trump Tower, at 56th Street and Fifth Avenue, on May 31, 2011, in New York City. Hide Caption 5 of 21 Photos: Donald Trump in the public eye Trump looks out the window of his limousine after visiting Newick's Lobster House on April 27, 2011, in Dover, New Hampshire. Hide Caption 6 of 21 Photos: Donald Trump in the public eye Trump speaks to the media at Pease International Tradeport on April 27, 2011, in Portsmouth, New Hampshire. Hide Caption 7 of 21 Photos: Donald Trump in the public eye Trump speaks to a crowd at the Palm Beach County Tax Day Tea Party on April 16, 2011, at Sanborn Square in Boca Raton, Florida. Hide Caption 8 of 21 Photos: Donald Trump in the public eye Trump and his wife, Melania, attend the Michael Kors Spring 2011 fashion show during Mercedes-Benz Fashion Week at The Theater at Lincoln Center on September 15, 2010, in New York City. Hide Caption 9 of 21 Photos: Donald Trump in the public eye Trump kisses Miss Universe 2009 Stefania Fernandez as they arrive at the 2010 Miss Universe Pageant at the Mandalay Bay Events Center on August 23, 2010, in Las Vegas. Hide Caption 10 of 21 Photos: Donald Trump in the public eye Trump and his children Eric (second from left), Ivanka and Donald Jr. attend the ribbon-cutting ceremony for Trump SoHo New York at Trump SoHo on April 9, 2010, in New York City. Hide Caption 11 of 21 Photos: Donald Trump in the public eye Trump, his daughter Ivanka, wife Melania and son Barron attend the "The Trump Card: Playing to Win in Work and Life" book launch celebration at Trump Tower on October 14, 2009, in New York City. Hide Caption 12 of 21 Photos: Donald Trump in the public eye Trump and professional tennis player Serena Williams attend the Gucci cocktail party for the Foundation For the Advancement of Women Now at Gucci Fifth Avenue on September 16, 2009, in New York City. Hide Caption 13 of 21 Photos: Donald Trump in the public eye Trump and his wife, Melania, left, attend the launch of Trump International Hotel and Tower Dubai with model Heidi Klum on June 23, 2008, at the Park Avenue Plaza in New York City. Hide Caption 14 of 21 Photos: Donald Trump in the public eye Trump attends the debut of a Lego replica of the Trump International Hotel & Tower Dubai on June 23, 2008, at Central Park in New York City. Hide Caption 15 of 21 Photos: Donald Trump in the public eye Trump attends the announcement of a partnership with Affliction Entertainment on June 5, 2008, at Trump Tower in New York City. Hide Caption 16 of 21 Photos: Donald Trump in the public eye Trump attends the Donald Trump Friars Club Roast Luncheon at the New York Hilton on October 15, 2004, in New York City. Hide Caption 17 of 21 Photos: Donald Trump in the public eye Trump poses with the new Donald Trump 12-inch talking doll on September 29, 2004, at the Toys 'R' Us store in New York City. Hide Caption 18 of 21 Photos: Donald Trump in the public eye Trump arrives at "The Apprentice" casting call in Trump Tower on July 30, 2004, in New York City. Hide Caption 19 of 21 Photos: Donald Trump in the public eye Trump dips Marla Maples after the couple married in a private ceremony amid tight security at the Plaza Hotel on December 20, 1993, following a six-year courtship. Hide Caption 20 of 21 Photos: Donald Trump in the public eye Trump and his wife, Ivana, arrive at a social engagement on December 4, 1989, in New York. Hide Caption 21 of 21

Trump asked Lewandowski if he was the best operative in New Hampshire, according to one source with knowledge of the conversation. He answered that he was the best in the country.

Lewandowski's brash confidence impressed Trump, and the interview lasted for a mere half hour: "You're hired," he told Lewandowski, who had previously worked for Americans for Prosperity, the Koch-brothers allied group, and had managed the failed re-election campaign of New Hampshire Sen. Bob Smith in 2002.

Though Lewandowski had four children at home in New Hampshire, Trump was eager to get started and wanted him in the New York office by the following week. They negotiated a round trip home every other week and the deal was done.

In those early days of 2015, Lewandowski was one of just a few people who knew something that the rest of political world refused to believe: Trump was deadly serious about a presidential run and confident that he could win the Republican nomination.

The signs of his intentions were all there. For several years, Trump had been elevating his stature as a top Republican donor, cutting a six-figure check to the Republican Governor's Association in 2014 and maxing out to the Republican National Committee — a status that warranted a courtesy call each September from Republican Party Chairman Reince Priebus.

Still, almost no one in the political world took Trump seriously. He had toyed with presidential runs before and dropped them. Republican insiders predicted he would never file the requisite financial paperwork, or wrestle with the complex process of qualifying for the ballot in all 50 states. The presumption among strategists at other campaigns was that he would bask in the burst of publicity around his candidacy and then go back to his gilded world in reality television -- likely after destroying his own campaign and reputation with his gaffes.

As late as last spring and summer, one bundler for former Florida Gov. Jeb Bush noted that Trump wasn't even described as a serious threat during presentations to Bush donors about the former Florida governor's chief rivals and obstacles ahead. Bush allies were far more focused on Rubio and Kasich, believing that those two candidates were in that establishment lane, and a challenge down the road from Cruz, with his conservative cache and well-funded operation.

As it turned out, Trump was in everyone's lane.

The real estate mogul's unsettling announcement speech on June 16 at Trump Tower -- where he described the U.S. as the "dumping ground for everybody else's problems" and cast Mexican immigrants as "rapists " -- underscored the perception in Republican circles that his candidacy would never survive.

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The business backlash to his anti-immigrant comments was swift. Univision canceled its telecast of the Miss USA pageant , which was partially owned by Trump. Macy's severed its business relationship with Trump and announced it would phase out his menswear line.

Through that controversy, Trump's poll numbers continued to rise -- the first of many times that he would defy political gravity.

Many Republicans were appalled in July when he questioned the heroism of Arizona Sen. John McCain , who was held as a prisoner of war during the Vietnam War. "I like people that weren't captured, OK?" Trump said during a Family Leadership Summit in Ames, Iowa.

Many thought that remark was the beginning of the end for Trump. It wasn't. Instead, it was another early sign that the normal political rules would not apply. "Traditionally, campaigns for president are a very high-stakes test of character," said Kevin Madden, a former campaign adviser to 2012 Republican nominee Mitt Romney and former President George W. Bush, and now a CNN political analyst. "He didn't pay a price for that."

Still, many conservative activists shrugged off "the Summer of Trump" — predicting that voters would get serious as the election drew closer.

The first CNN debate in September was a wake-up call to some party leaders, drawing 23 million viewers as Trump railed against immigration and dragged other candidates to the right, unraveling the careful ground work the party had laid after its 2012 loss to try to rebuild the Republican brand among fast-growing minorities such as Latinos.

Photos: Who's running for president? Photos: Who's running for president? Ted Cruz, Donald Trump, John Kasich, Hillary Clinton and Bernie Sanders, Hide Caption 1 of 6 Photos: Who's running for president?



"So, ladies and gentlemen, I am officially running for president of the United States, and we are going to make our country great again," Trump told the crowd at his announcement. Businessman Donald Trump announced June 16 at his Trump Tower in New York City that he is seeking the Republican presidential nomination. This ends more than two decades of flirting with the idea of running for the White House."So, ladies and gentlemen, I am officially running for president of the United States, and we are going to make our country great again," Trump told the crowd at his announcement. Hide Caption 2 of 6 Photos: Who's running for president?



"These are all of our stories," Cruz told the audience at Liberty University in Virginia. "These are who we are as Americans. And yet for so many Americans, the promise of America seems more and more distant." Sen. Ted Cruz of Texas has made a name for himself in the Senate, solidifying his brand as a conservative firebrand willing to take on the GOP's establishment. He announced he was seeking the Republican presidential nomination in a speech on March 23."These are all of our stories," Cruz told the audience at Liberty University in Virginia. "These are who we are as Americans. And yet for so many Americans, the promise of America seems more and more distant." Hide Caption 3 of 6 Photos: Who's running for president? Ohio Gov. John Kasich joined the Republican field July 21 as he formally announced his White House bid.



"I am here to ask you for your prayers, for your support ... because I have decided to run for president of the United States," Kasich told his kickoff rally at the Ohio State University. Hide Caption 4 of 6 Photos: Who's running for president?



"Everyday Americans need a champion, and I want to be that champion -- so you can do more than just get by -- you can get ahead. And stay ahead," she said in her announcement video. "Because when families are strong, America is strong. So I'm hitting the road to earn your vote, because it's your time. And I hope you'll join me on this journey." Hillary Clinton launched her presidential bid on April 12 through a video message on social media. The former first lady, senator and secretary of state is considered the front-runner among possible Democratic candidates."Everyday Americans need a champion, and I want to be that champion -- so you can do more than just get by -- you can get ahead. And stay ahead," she said in her announcement video. "Because when families are strong, America is strong. So I'm hitting the road to earn your vote, because it's your time. And I hope you'll join me on this journey." Hide Caption 5 of 6 Photos: Who's running for president?



"This great nation and its government belong to all of the people and not to a handful of billionaires, their super PACs and their lobbyists," Sanders said at a rally in Vermont on May 26. Sen. Bernie Sanders , an independent from Vermont who caucuses with Democrats, announced his run in an email to supporters on April 30. He has said the United States needs a "political revolution" of working-class Americans to take back control of the government from billionaires."This great nation and its government belong to all of the people and not to a handful of billionaires, their super PACs and their lobbyists," Sanders said at a rally in Vermont on May 26. Hide Caption 6 of 6

The other campaigns were keyed in to the electorate's anti-establishment mood — trying out various versions of Trump's message. Bush tried to cast himself as the disrupter. Rubio played up his credentials as an insurgent upstart from Florida while flying under the radar with the light footprint of his campaign. Cruz bragged about his independence from "the Washington cartel." Kasich called for returning power to the states.

Candidates like former Texas Gov. Rick Perry , who went hard at Trump, were forced from the race.

"They all bought into the idea that Trump wasn't their problem," Madden said. As Trump slayed one adversary after another and continued to rise in the polls, the risks of taking him on seemed to outweigh the potential upsides.

Cruz would ultimately build the strongest effort to stay in the ring as Trump rose, with a strategy of "drafting" behind Trump (as the second-place car does behind the lead car in a NASCAR race) — sharing the same issue set, refusing to attack Trump, even appearing alongside him at an Iran rally in Washington — riding just behind him in the hope he could ultimately slingshot past him.

The only candidate who stayed on offense was Trump.

Other campaigns tried to adapt to Trump's dominance in the media cycle by making their candidates more visible through cable interviews and trying to break into the news by using the latest Trump controversy as a foil. The only candidate who really tried to confront Trump was Bush, but Trump repeatedly got the better of him in those exchanges.

Several former Bush operatives noted that the former Florida governor was the worst messenger to stop Trump's rise because of his brother's presidency and his indisputable ties to the establishment.

Strategists from all the leading campaigns also complained that reporters covered Trump with a different standard, reporting on him as a spectacle rather than a serious presidential contender.

"Everybody should have been challenging Trump from the start. We should have done more," one Bush adviser said, asking not to be named questioning the campaign's strategy. "He was able to grow this support and the armor that comes with it before anyone started punching him. There was a missed opportunity to run a sustained campaign against him from the start."

By early this year, the view that Trump was Teflon made donors skittish about taking him on. The influential Koch organizations came close to running an extensive multi-million-dollar campaign against him. It would have tried to expose him as the operator who had worked government to hurt the little guy and help the elites, said a source who was familiar with the plans. It was poll-tested. But just before the South Carolina primary, the organization decided it carried too much risk of damaging their outsider brand with voters that they had so carefully cultivated during the midterm campaigns and by staying out of Republican primaries.

As late as January, political operatives addressing a gathering of Koch network donors in California told them Trump had "a chance" of winning the Republican nomination, but said "the odds were still against it," according to a participant who listened to the presentation.

The end-run

By the time that Trump began notching sizable victories in New Hampshire, South Carolina and Nevada, the second-guessing about the strategy used against him -- or lack thereof -- was well underway within all the campaigns and among outside groups set up to boost the top candidates.

Though time was slipping away, the anti-Trump donors poured money into Our Principles PAC, the group that organized the donor call on Super Tuesday and its related conservative non-profit group(c)(4) organization, American Future Fund.

They husbanded their resources by airing ads and doing sophisticated microtargeting of voters only in states where one of the top candidates — Kasich, Cruz, or Rubio — had a chance of beating Trump or picking up a sizable share of delegates. That meant states like Idaho, Florida, Ohio, Illinois and Missouri.

The group organized robocalls to conservative voters that featured Trump in his own voice telling Tim Russert in 1999 on "Meet the Press" about his support for abortion (without explaining Trump's conversion on the issue).

Taking a page from the 2012 Obama playbook against Mitt Romney — who began making a late but forceful case against Trump in March — American Future Fund found Americans who told stories about being scammed by Trump as they looked directly at the camera.

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Some ads from anti-Trump forces detailed the lawsuit around Trump University; others highlighted the alarming eruptions of violence at a recent Trump rally in Chicago and his derogatory comments about women.

The goal was to raise doubts about Trump's electability and his character. The anti-Trump groups were not trying to dissuade the 30-something percent of voters who were loyal to Trump, or target the portion of the Republican electorate that was already dead set against him. Their goal: cap Trump's support among the somewhat conservative voters in the middle, who remained amused and entertained by Trump but weren't ready to support him.

While those super PAC efforts were under way — a joint effort of donors who had supported Bush, Rubio, Cruz and Kasich — the Kasich, Cruz and Rubio campaigns focused on a more targeted strategy of sweeping up delegates to deprive Trump of the 1,237 he would need to win outright.

Cruz went hard in Wyoming — where he won nine of the 12 delegates that were contested on Saturday — while Rubio's campaign pulled out all the stops to win the caucuses in Washington, D.C., picking up 10 delegates.

But Florida remained Rubio's must-win state, and his shattering defeat Tuesday night — 27% to Trump's nearly 46% with 98% of the vote counted — was perhaps the most surprising. He had been the last to take on Trump and seemed poised to finally seize the buzzy moment that his campaign had counted on to give him a jolt of momentum in early 2016.

But some voters recoiled at the vulgar exchanges between the charismatic Florida senator and Trump. Not only did it cut against Rubio's brand, but he also seemed late to the game. Voters questioned why he had waited so long to take on Trump.

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From a tactical standpoint, the Rubio campaign's strategy of keeping a light footprint ran into deep trouble in Florida.

It had made sense earlier in the race when his rivals appeared to be a crop of candidates whose political skills and media savvy weren't as sharp as his own. But that strategy faltered as Trump grew stronger, particularly in Florida -- where no one had imagined the need to roll out such an extensive ground game.

The initial game plan, one Rubio ally said, "did not take into account" that Rubio "was not going to be the earned media darling of the campaign." "In a race against Jeb Bush, Scott Walker and Ted Cruz -- that's a totally different race than one against Donald Trump," this Rubio ally said. Like his rivals, Rubio failed to adjust when the reality of Trump upended expectations.

When Rubio arrived in Boise, Idaho, as recently as last week, he was brimming with confidence -- believing the state would deliver him a crucial win, marking a victory that could give him some much-needed momentum heading into the Florida primary a week later.

He dropped nearly six figures on a late ad buy in Idaho's cheap media markets, hoping to give a dose of energy to his rocky campaign. And he had the backing of the state's conservative senator, Jim Risch, an early supporter who knew the state better than just about anyone.

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"Idaho has the chance to restart this campaign," an ebullient Rubio told supporters at Boise State University.

Instead, Idaho may have helped kill his campaign. Rubio was trounced, coming in a distant third place and losing by 30 points to Cruz and 12 points to Trump. It helped capped a miserable night for Rubio, when he failed to win a single delegate of the four states that voted -- ratcheting up pressure to win his home state a week later or quit the race.

Rubio's loss in Florida was a stunning home-state rejection of an eloquent and fresh-faced politician groomed to lead a fractured Republican Party into the next century and define the next generation of conservatism.

"I really believe that if Donald Trump wasn't in this race, Marco Rubio would be the nominee today," Risch said. "This is the most unusual set of circumstances I've ever seen in my life."

As Rubio's campaign headed into the painful final days of the campaign in Florida, the senator and his senior staff struggled to come to grips with what was happening. Rubio, speaking to reporters and voters, didn't hold back his exasperation: Trump represented everything that he believed was wrong about politics. He was vain and self-absorbed, Rubio said, a man who perpetuated hate and would destroy the Republican Party. Yet, Trump was winning and winning big.

"We have a culture today -- what used to be wrong is now considered right," Rubio told supporters in West Palm Beach Monday, recalling how nearly a year ago he launched a presidential bid defined by hope and optimism. "My whole life I have been told no matter how you may feel about someone, you respect everyone because we are all children of the same God."

He warned that those kinds of politics would leave America "a fractured nation." Rubio's concession speech rebuked Trump's divisive tactics.He warned that those kinds of politics would leave America "a fractured nation."

"America is in the middle of a real political storm, a real tsunami," Rubio said Tuesday night, "and we should have seen this coming."