Republican insiders told ABC News that U.S. Sen. Marco Rubio, R-Fla., has not been asked to turn over typical vetting documents to the Romney campaign. Reuters

All eyes are on junior U.S. Senator Marco Rubio, R-Fla.

Though he declines to discuss it, Rubio looks like a top contender for the vice presidential nomination under presumptive Republican presidential candidate Mitt Romney. Rubio has lately been appearing on talk shows to push his own credentials, despite the fact that he is not officially running for office.

I certainly am not the most experienced person in Washington, D.C. But by the same token, I certainly have experience serving in government and particularly in the legislative branch in one of the largest states and more complex states in the country, in terms of public policy, said Rubio during a Sunday television appearance on Fox News.

To many political commentators, those are the words of a hopeful second-in-command. And for Marco Rubio, it wouldn't be a long shot. He could be just the man Romney needs to convince the American electorate to vote him into office this November.

No More Mr. Moneybags

One of the most prominent criticisms leveled against Romney is that he is out of touch with working-class Americans due to his wealth. Romney, who estimates his own worth at between $190 million and $250 million, has made plenty of gaffes suggesting that he does not understand the extent of Americans' struggles during this recession. He has casually noted that his wife owns a couple of Cadillacs, called corporations people, and even said during a televised interview that he was not concerned about the very poor.

Rubio, on the other hand, has a more relatable background. I pinch myself because of the understanding that I've been blessed with a real rare opportunity that few Americans ever get, to serve their government and their people at this level, he said. It doesn't escape me that less than half a decade ago, my family lived very different circumstances. My dad was a bartender. My mom was maid.

Rubio's is the kind of story that may appeal to working class voters, even if Romney himself can't bridge the gap.

El Voto Latino

About 16 percent of the U.S. population identifies as Hispanic, but appealing to this important bloc of voters seems all but impossible for Romney. Rubio could turn out to be a secret weapon.

Recent polls show that in general, Hispanic voters are strongly in favor of a second term for Obama. One poll, conducted by Fox News Latino, showed that Latino voters across the country overwhelmingly support the DREAM Act, (90 percent), favor a path to citizenship for undocumented immigrants (85 percent) and believe undocumented workers help to grow the U.S. economy. On all of these issues, the Obama administration has been more in accordance with Latino voters than Romney seems to be.

Though he agrees with Romney on many important issues, Rubio's Cuban heritage may help him connect with Latino voters on a more personal level. Poll results indicated that nearly one fourth of Latino voters would be more willing to cast a GOP vote if Rubio was the vice presidential candidate.

The Right Lean

During his primary battles against Rick Santorum, Romney struggled to appeal to died-in-the-wool social conservatives. Now that Santorum is out of the picture, Romney can more safely tack left in order to woo swing voters. But he still needs to generate a strong November turnout among the Republican base, and Rubio may help him achieve that.

Romney was once an independent. Even after becoming a Republican, he had to stay moderate in order to govern the traditionally blue state of Massachusetts. There, he sponsored what has been called the blueprint to Obama's healthcare overhaul plan. To conservatives, this record is less than ideal. Romney has been called a flip-flopper and accused of feigning conservatism only when it's politically necessary.

Rubio, on the other hand, has a solidly conservative record. He has voted against gay marriage, against contraceptive healthcare requirements, and against taxes on capital gains. He has supported greater local control over education, cutbacks in federal spending, and the adoption of a balanced-budget amendment.

A record like that could add some conservative weight to Romney's presidential ticket.

Back To Life

Politics aside, Romney has struggled even to convince voters that he's a likeable guy. He never looks quite natural, whether he's speaking from behind a podium or trading jokes with voters across America. He has been called stiff, robotic and even soulless. Awkward campaign moves include adopting the term 'y'all' while campaigning in Southern states, painfully rendering an entire verse of 'America the Beautiful' onstage, and remarking that one famous pastry shop's cookies looked like they came from 7-11 bakery.

Rubio, by contrast, is considered young and charismatic. Even political opponents have called him smart, charming and smooth. If he is chosen for the GOP 2012 presidential ticket, he could bring just the kind of spark Romney needs to liven things up.