Marco Rubio: The Republican of the moment
Marco Rubio speaks during the CNBC Republican Presidential Debate, October 28, 2015 (AFP Photo/Robyn Beck)

As a child, Marco Rubio assured his exiled grandfather he would overthrow Fidel Castro to lead Cuba. Today at 44, he aspires to lead the United States, and he inched closer to that dream with a breakout performance in Wednesday's Republican debate.

After months of toil on the campaign trail, the Florida senator finally seized his moment in the 2016 presidential race at the primary debate in Colorado, where commentators said he won the night.

A small-government conservative, Rubio had newly surged into third place in Republican polls, overtaking his one-time mentor Jeb Bush to snap at the heels of Donald Trump and Ben Carson.

And it was the son and brother of two presidents who inadvertently provided Rubio's springboard for success when he took a shot at the junior lawmaker for missing Senate votes in favor of campaigning.

"I will continue to have tremendous admiration and respect for governor Bush," Rubio said, deftly deflecting the attack.

"I'm not running against governor Bush, I'm not running against anyone on this stage," he added. "I'm running for president because there is no way we can elect (Democratic frontrunner) Hillary Clinton to continue the policies of Barack Obama."

The reasoned, confident dispatch of a frontal attack was the first of many quality turns in the two-hour showdown, putting Rubio's shrewd political skill on clear display among the 10 on candidates stage.

Several commentators suggested the clash may be what triggers the unravelling of a Bush campaign which has failed to enthrall.

Outsider candidates Trump and Carson, meanwhile, came under attack for their "fantasy" tax plans and political inexperience.

The brash billionaire Trump and retired neurosurgeon Carson were largely marginalized on stage, and their lackluster performances helped the establishment politicians strike back.

- Cuban son -

Marco Rubio was born in Miami in 1971, the son of poor Cuban refugees who fled the island 15 years earlier to escape poverty.

After Castro seized power in 1959, the family decided never to return to Cuba, a country Rubio has never known.

But Cuba is a recurring theme for the first-term senator, whose ambitions reflect those of generations of refugees eager to carve out better lives in America.

"I am the son of immigrants, exiles from a troubled country," he wrote in his 2012 memoir, "An American Son."

"They gave me everything it was in their power to give. And I am proof their lives mattered, their existence had a purpose."

The son of a bartender and a housemaid, Rubio grew up in Miami's Cuban-American community, although the family spent five years in Las Vegas, where they converted briefly to the Mormon faith before returning to Catholicism.

Influenced by his grandfather, who spoke no English, Rubio developed a passion for politics. He was a fan of Senator Ted Kennedy, a Democratic icon, before falling hard for Republican president Ronald Reagan.

Americans nationally learned of Rubio in 2010 when as an underdog he spectacularly won election to the Senate, riding the Tea Party wave that sent several advocates of small government to Congress.

Many envision him becoming the nation's first Hispanic commander-in-chief, in a rags-to-political-riches story embodying the American Dream.

Just two years after earning a law degree, he was elected in 1998 to the West Miami City Commission. A year later, it was Florida's House of Representatives, where he rose to become speaker in 2006.

Rubio is a compelling package: charismatic with an engaging smile and snappy oratory.

He breaks the traditional social conservative mold: he goes to church with wife Jeanette and their four children, but since childhood he has been a hip-hop fan, often hailing genre pioneers Grandmaster Flash and Tupac Shakur.

And he is bilingual, a major asset for the Republican Party, which has felt the sting of Hispanic voter abandonment.

- Interventionist -

On his arrival in Washington, conservatives traumatized by Obama's election believed they had found their savior.

But his Tea Party support plunged in 2013 after he helped craft comprehensive immigration reform that would have legalized millions of undocumented migrants.

Rubio has sought to recover. While backing off his immigration plan, he engages in other substantive legislative efforts, ostensibly to prove that beyond his formidable communication skills he can lead a conservative renewal.

He has unveiled proposals to reduce poverty and introduced pension system reforms -- without forgetting fundamental conservative values like traditional marriage.

"We need to recognize societal breakdown, the fact that too many Americans in childhood are not acquiring values like hard work and sacrifice and self-control," he told AFP in 2013.

Rubio champions an aggressive foreign policy and muscular defense.

More interventionist than isolationist, he argues that global flashpoints require Washington to be more engaged abroad.

And yet he seeks to place Cuba in the same category as Iran -- isolating it at all costs -- and has led opposition to Obama's detente with the island of his ancestors.