Does the GOP still see Marco Rubio as the answer to its problems?

Three years ago, Sen. Marco Rubio was heralded as the Republican Party's savior.

After the GOP's stinging 2012 presidential loss, strategists prescribed the charismatic, young tea party favorite as the antidote to a fractured party — someone who could even expand the base by attracting Latino voters.

He so dazzled the 2012 Republican National Convention when he introduced Mitt Romney that some called the boyishly-handsome conservative a transformational GOP candidate not seen since Ronald Reagan — or Obama for Democrats.

But as the 43-year-old Florida senator prepares to announce his presidential bid Monday, the early buzz has faded and, after a political misstep over immigration reform, Rubio finds himself just another name in an increasingly crowded field of 2016 presidential rivals who have chipped away at what were once seen as his strongest assets.

Former Gov. Jeb Bush, with his unmatched fundraising juggernaut, knocked off Rubio as the GOP establishment favorite. Sen. Ted Cruz (R-Texas) is stealing the hearts of evangelicals and tea party activists. Wisconsin Gov. Scott Walker is the new fresh face.

Rubio is now seen by many as a sleeper candidate or second-choice. As his campaign ramps up, it will need to reignite the excitement that once led the party to view him as a front-runner.

Rubio's backers predict he will do exactly that, repeating his 2010 come-from-behind Senate victory with the first tea party wave.

"He's proven time and time again he's the comeback kid," said Nick Iarossi, a Florida lobbyist for casino mogul Sheldon Adelson. "Anyone who would underestimate him does so at their peril."

But recent polling has found that Rubio — who ranked No. 2 in a 2012 national presidential survey of Republican voters — is languishing in fifth or sixth place behind Bush, Walker and others.

Even Rubio's hot-streak among Latino voters cooled after he stumbled badly in 2013 by first proposing, and then abandoning, a sweeping immigration reform plan. The debacle left both sides feeling betrayed in a national problem Rubio was once seen as uniquely suited to help resolve.

"He's going to have a very hard time getting back to his high mark," said Matt Barreto, a UCLA political science professor and co-founder of polling firm Latino Decisions. He noted that Rubio's attacks against President Obama's executive actions deferring deportations have cost Rubio support in Latino communities.

Many conservatives, meanwhile, haven't forgiven Rubio for joining Senate Democrats in passing the now-dead bipartisan plan that would have created a citizenship pathway for immigrants who are in the country illegally. Critics blasted it as "amnesty." Rubio was even booed at a 2013 conservative forum sponsored by the Koch brothers-backed Americans for Prosperity.

"It's a wart on an overall positive story," said Michael A. Needham, CEO of the conservative Heritage Action for America, the political arm of the influential think tank.

Rubio has tried to move on from the issue, saying he miscalculated Americans' desire to first tackle border security. But as he becomes the third official Republican candidate for 2016, the issue is certain to follow the man who dreams of being the first Latino presidential nominee of one of the two main parties.

Rubio's team takes the long view — promising a campaign that is not seeking flash and sizzle, but will pursue a steady build they hope will culminate with a mandate. He's quietly amassed a strong campaign team, many coming from Mitt Romney's 2012 presidential bid. To bolster his policy credentials, the freshman senator recently rolled out a series of position papers and a new book, "American Dreams," in which he takes his own party to task for outmoded policy thinking.

"He's a do-er, Marco Rubio," said billionaire auto dealer Norman Braman, who has pledged substantial backing for the campaign, in an interview. "He's the only Republican candidate that is acceptable to all branches of the Republican Party: the establishment groups, the tea party groups, the libertarian groups."

Rubio's only-in-America personal narrative as the son of immigrants — his father was a bartender, his mother a maid — is expected to weigh heavily in the campaign.

Miami's Freedom Tower, the venue for Monday's speech, is known as the Ellis Island of the South, or "El Refugio," for housing federal assistance services to Cuban refugees.

"He has a true gift for communicating the American story," said Rick Wilson, a Republican consultant in Florida.

While his parents struggled to provide for the family, Rubio acknowledged in his 2012 autobiography "An American Son" that they doted on their youngest boy so much it left him rather spoiled.

A self-described "brat," he recalls childhood tantrums over delays in being served his after-church pancakes at an IHOP restaurant. Rather than admonish Rubio for his impatience and rudeness, his father politely asked if the waitress could hurry it up.

Later he begged his parents to send him to a private Catholic school they could scarcely afford, but then switched to public junior high after discovering how strict it was.

By his own admission, his early scholastic career was unimpressive as he partied through high school and parts of college, turning to study political science at University of Florida only after his dreams of being a pro-football star fizzled with an injury and the realization he wasn't good enough.

While some politicians build a career rooted in ideology, Rubio's political ambitions seem to have evolved from a desire to make something of himself. "I have been ambitious for worldly success," he writes. "I hope I have been for the right reasons."

His early political career was aided by the backing of prominent local leaders in Miami who helped the young conservative to become the first Cuban American speaker of the Florida state house at age 35.

His conservative streak began with long childhood talks with his Cuban American grandfather, whose hawkish, anti-communist views hardened after the rise of Fidel Castro. As a child, Rubio and most of the family briefly joined the Mormon church while living in Las Vegas for five years. Young Marco threw himself into the new religion, nagging his father to give up smoking and condemning the bartending job as "sinful," Rubio writes.

Today Rubio, married and the father of four young children, attends his wife's Christian church and remains a practicing Catholic.

He cites his faith for his opposition to abortion and same-sex marriage. He sided with defense hawks last month in seeking to boost Pentagon spending, parting ways with Cruz and Sen. Rand Paul (R-Ky.), who voted against the budget. Earlier this year Rubio voted against renewing funds to keep open the Homeland Security Department to protest Obama's immigration plan.

Some have questioned whether Rubio has the experience or commanding presence Americans expect of their president. His awkward reach for a bottle of water in the middle of his GOP response to the 2013 State of the Union address went viral.

His new book, intended to be a vehicle for serious policy, is long on goals if short on groundbreaking ideas. He taps into familiar Republican proposals, including Sen. Paul Ryan's (R-Wisc.) prescription for overhauling Medicare, and criticizes conservatives for wanting to cut social programs they oppose, rather than re-imagining ways they could work better.

After the 2013 immigration debacle, Rubio retreated from the limelight, hunkering down to rebuild his image. He spoke to tea party groups in Florida, and reemerged at carefully orchestrated national forums. He reflects on his past slip-ups with a self-effacing sense of humor — poking fun at himself, for example, by selling signed water bottles on his website.

But while he has been regrouping, Rubio's GOP rivals have shored up their pathways to the nomination, luring away constituencies that Rubio will need to win. The presumed entry of Bush makes it particularly difficult for Rubio to even capture his own state of Florida, where the Bush family ties are deep.

So far, Rubio has avoided criticizing any of his potential Republican rivals, focusing instead on Democratic front-runner Hillary Clinton, who entered the race Sunday. Rubio calls her "yesterday," and portrays himself as the 21st century leader.

But the promise Rubio once brought in courting Latino voters is in doubt. Whit Ayres, a Republican pollster working with Rubio, has said the next Republican candidate will need more than 40% of the Latino vote to win the party's nomination – a well-known formula that no candidate has been able to achieve since President George W. Bush.

But Rubio's chances of reaching that benchmark are dim. Polling showed that in 2013, when Rubio pushed his immigration plan, 54% of Latino voters were likely to consider him for president, according to Latino Decisions. But when told that Rubio had ultimately switched course on the immigration effort, the numbers reversed, and 65% said they weren't likely to give him a look.

"If he ran on his best rhetoric in 2013, he would have a chance to connect with Latino voters," said Barreto, the group's co-founder. "The problem is, the party voters won't let him do that."