On paper, no engineer could have designed a better Republican candidate for the 21st century than Marco Rubio. He was the fresh, young face of the Grand Old Party—right up until the minute he became the latest gobsmacked visage of its tired old past.

Rubio, his super-PAC, and other allied supporters raised more than $84 million—the equivalent of Eli Manning’s latest four-year contract extension with the Giants—yet managed to win only three contests: Minnesota, Puerto Rico, and the District of Columbia, a Walter Mondale–esque electoral performance if ever there was one. But even Mondale carried his home state against Ronald Reagan in 1984 (albeit barely), something Rubio could not manage to do in the Florida primary, where Donald Trump’s triumphant juggernaut won all 99 Republican delegates on Tuesday. Looking all too much like the “Little Marco” Trump had dubbed him, he bowed to the inevitable and dropped out.

“There is nothing more you could have done,” he told his supporters in Miami, invoking what he called the political tsunami that has been the 2016 campaign. “We should have seen this coming.”

But Rubio was far from alone in failing to foresee his fate. His defeat was just another “How could this have happened?” moment in a head-scratching year. In the waning days of his campaign, he took to saying that, come January, “I will either be president of the United States or I will be a private citizen.” But he never expected to be a political has-been at 44.

In the wake of Mitt Romney’s resounding 2012 defeat, some of the G.O.P.’s sharpest analysts conducted an autopsy that called for a retooled Republicanism, to be led by a conservative but optimistic standard-bearer who could appeal to an electorate growing steadily younger and more diverse. Rubio, the Catholic self-made son of a Cuban-émigré bartender and a hotel maid, seemed tailor-made for the part.

Time hailed him as “The Republican Savior,” and Hillary Clinton’s advisers acknowledged that he struck some fear in their hearts. At 27, he had been the youngest-ever speaker of the Florida House of Representatives, and the first-ever Latino, to boot. Propelled to the Senate on the Tea Party wave of 2010, (and endorsed then by the unlikely trio of Mitt Romney, Dick Cheney, and Sarah Palin), he nevertheless declined to join the congressional Tea Party caucus once in office. He still racked up a nearly perfect conservative score on social issues, according to *National Journal’*s annual rankings.

Arguably his best, and worst, moment was his work with the bipartisan “Gang of Eight” to forge an immigration reform plan that envisioned a path to legal residency—and ultimately citizenship—for undocumented aliens who met a series of strict tests. But he backed away from the effort when the party’s right wing went ballistic, making both his embrace and rejection of the issue look opportunistic.

The immigration issue dogged him all through the primary season as he struggled to explain his position. And he struggled in other ways, too—first, in the race, for money against his fellow Floridian and onetime mentor Jeb Bush; then for the mantle of true conservative against his fellow Cuban Ted Cruz; and finally for traction against Trump and the splintered field of conventional candidates.

In some ways, Rubio never recovered from Chris Christie’s murder-suicide attack on him in the final debate before the New Hampshire primary, in which the governor of New Jersey portrayed him as a “boy in the bubble,” incapable of uttering anything other than canned talking points and carefully rehearsed one-liners. Rubio’s response? A nervous, fumbling series of canned talking points and rehearsed one-liners. And then there was his descent into potty-mouth, playground taunts against Trump—a decision that made him look at once desperate and slightly deranged, since he also acknowledged in the next breath that he’d probably have to vote for the guy if he became the nominee. Reagan-esque he was not.

There was always the question of whether an electorate now all too aware of Barack Obama’s pre-presidential lack of managerial experience would go for another first-term senator who had never run anything bigger than his own campaign. But Team Rubio assumed that would be a question for November, not February or March.

Life is long, and anyone who would count Rubio out of the game for good should remember just two words: Dick Nixon. Maybe he’ll run for governor of Florida in 2018, redeem himself and come back older and wiser in four or eight years. That would be the traditional Republican way.

But only last fall, Rubio’s pollster Whit Ayres, in a not-so-subtle dig at would-be establishment heirs apparent like Jeb Bush, told me that his party could not prosper by continuing in the old way. “You can’t look at what’s happened over the last 20 years in this country and conclude that we will be successful in nominating the same kind of candidate we’ve nominated in the past,” Ayres said. “The country has changed, and we need to change with it.”

Rubio thought he understood that, and maybe he did. As it turns out, Donald Trump just understood it better.