With a sudden outpouring of money and endorsements flowing to
The only problem with the plan: Rubio has yet to win a single state.
And no one seems certain when, or where, he will.
Nevada was once thought to be almost a sure bet for Rubio, even if he failed to win in early states Iowa and New Hampshire.
But despite a heavy investment by Rubio in Las Vegas, where he spent part of his childhood, voters handed Trump a big victory Tuesday.
The senator from Florida has spun his early-state failures into success stories, insisting his second- and third-place finishes prove he is the party's top alternative to Trump and the only candidate who can bring together the party's splintering factions.
Backers say they always expected Rubio to trail early and then gradually build momentum.
Even in defeat, Rubio has endeavored to give his campaign an air of inevitability. "Our campaign gives us the best chance, not just to come together, not just to unify our party, but to unify our country and to grow this movement," he said after his second-place showing in South Carolina.
Tuesday night, Rubio went to bed without making a statement, his campaign spokesman said.
Outside Rubio's campaign, however, strategists and others looking for a way to halt Trump's seemingly unstoppable rise point to the obvious: He can't win the nomination by forever coming in second.
"To win, you have to win. And you don't win by doing well," said Stuart Stevens, the top strategist to Mitt Romney's 2012 campaign.
Despite his campaign's claims of "Marco-mentum," it is Trump, not Rubio, who is amassing the necessary delegates. Polls show that a growing number of Republicans believe Trump will be the nominee, while Rubio continues to be most voters' second choice.
"We're past the point of trying to lower expectations," said Kevin Madden, a GOP consultant and Romney's former spokesman. "When you've got someone with Donald Trump's momentum, you've got to start beating expectations."
By contrast to Trump's bravado about winning, Rubio's campaign won't even say when or where their candidate might finish first in a state primary.
On Wednesday, Rubio heads to a rally in Minnesota, one of the large number of states voting on March 1, where his more measured brand of conservatism may have a good chance. Many in the GOP say he'll need to win at least one or two of the March 1 contests or risk falling hopelessly behind.
Trump and Sen.
Critics of Rubio's approach offer lots of advice. Stevens dismissed Rubio's campaign as a "branding exercise," with too much focus on crafting an optimistic message and holding festive, music-filled rallies: "That's great — and then they lose."
To win, Stevens says Rubio needs to take a more confrontational approach against Trump.
"Campaigns are fights," he said. "And not fighting Donald Trump — not fighting the person that's winning — means you're fighting for second, third, fourth place."
Trump's unexpected popularity upended Rubio's carefully laid campaign plans. For one thing, Trump's brash style pushed Rubio to strive to look and sound tougher, shifting from the Reaganesque optimism that he originally hoped to convey. Over the last weeks, Rubio has hardened his positions on immigration and joined Trump in bluntly calling Cruz a liar.
Trump's successes have also forced Rubio's campaign to rethink its electoral math.
Early on, Rubio's team privately acknowledged that its goal was simply to do well enough in Iowa and New Hampshire to amass enough cash and support to push forward to expected victories in South Carolina and Nevada. This was soon dubbed the 3-2-1 strategy, for his third-, second- and first-place hopes.
But after Rubio's near-fatal stumble in the New Hampshire debate helped land him in fifth place, and Trump dominated South Carolina despite Rubio's slate of high-profile endorsements, rivals and critics began mocking it as a 3-5-2 plan.
"I've been baffled this entire campaign by this obsession these campaigns have by trying to determine the order of losing, instead of trying to win," Stevens said.
Polling data from South Carolina showed that Rubio's support there was highest among GOP voters who believe he is best poised to beat the eventual Democratic nominee. But it remains unclear whether Rubio can expand the party's base by drawing in young people and minorities, as was once hoped.
Campaign officials say they are not worried.
"Republican voters are starting to realize across the country, if you don't want Donald Trump to take the nomination, you better get on Team Marco," said Rubio spokesman Alex Conant. "The key to us was to clear the field and get in a one-on-one campaign with Trump, and that's what's happening."
Former Florida Gov. Jeb Bush's exit Saturday from the race has helped, allowing high-dollar donors whose loyalties had been split between the two Floridians to turn to Rubio's side. Many now expect Bush to endorse Rubio.
Rubio has racked up endorsements from several prominent senators as well as Arkansas Gov. Asa Hutchinson and former Minnesota Gov.
"People are coming out to back Marco all over the country right now," said Rick Wilson, a longtime Republican consultant in Florida who runs a pro-Rubio super PAC. "People are realizing Marco Rubio is the one guy who can beat Donald Trump, and he beats
But few are predicting outright wins for Rubio in any of the upcoming contests, largely because the anti-Trump vote continues to be divided among Rubio, Cruz, Ohio Gov.
That means Rubio may not see a clear victory until he competes in his home state of Florida on March 15, widely seen as a must-win.
But by then, campaign veterans warn, it may be too late.