The junior U.S. Senator from Florida seems to have all the goods -- he's attractive, charismatic, and a rising star in the Republican party.
And while all those ingredients have propelled Marco Rubio's name to the upper ranks of those who might be the GOP vice presidential candidate, that star quality may also be what disqualifies him.
Likely GOP presidential nominee Mitt Romney's choice of a running-mate — a search he announced Monday he has begun — will be guided by both his methodical, risk-averse corporate training and the lessons his party learned from Sarah Palin's selection.
Preparedness to serve and loyalty to Romney are likely to trump other credentials as the all-but-sure Republican nominee looks to avoid the blowback John McCain faced four years ago with his surprise choice of the little-known, first-term Alaska governor for the GOP ticket. Questions about Palin's readiness to serve, McCain's decision-making and his advisers' vetting came to define the Arizona senator's flawed campaign.
Mindful of that, Romney will put experience at the top of his list of qualities as he chooses a No. 2, according to senior advisers and GOP operatives familiar with his thinking. They spoke on the condition of anonymity because they were not authorized to speak candidly about a process Romney himself is trying to keep as private as possible as he works to narrow a field that may begin with as many as a dozen prospective candidates.
"The hallmark for Governor Romney's candidacy, and how he would be as president, is that he approaches these decisions in a well-thought-out methodical way," said Steve Duprey, a former McCain adviser and current New Hampshire-based member of the Republican National Committee. "It won't be like the McCain campaign where there was a big surprise and effort to create a game changer."
For all the secrecy surrounding the process, the former Massachusetts governor did give a few hints about his plans Monday, disclosing that he had chosen his former chief of staff and 2008 presidential campaign manager, Beth Myers, to lead the vetting and analysis of prospective running mates. Several other members of the tight-knit cadre that has surrounded Romney for years also are likely to be involved.
Romney was largely tight-lipped beyond the staffing announcement. He said the selection would certainly happen before the Republican National Convention in late August. But he wouldn't provide any more guidance on any internal deadline his team has set. And when asked about potential choices — and Rubio, specifically — Romney hedged, as he has consistently in recent months.
"Well I think he's one of the terrific leaders in our party, but I think it's way too early to begin narrowing down who the potential vice presidential nominees might be," Romney said in an interview with Diane Sawyer of ABC News outside Fenway Park in Boston.
"But we're beginning that process, we'll talk about a lot of folks, and then go through he kind of vetting and review process that you have to go through to make sure whoever you select will pass the evaluation that's required by the American people."
In addition to his running mate being prepared to assume the presidency, Romney has laid out only one other public criterion: that he or she oppose abortion rights. The condition could help reassure social conservatives that Romney is serious about his opposition to abortion — a sore point because he supported abortion rights when he ran for the Senate in 1994.
Several Republicans familiar with Romney's thinking downplay the importance of choosing a running mate from a particular battleground state or an important voting demographic.
Romney also is expected to avoid a candidate with the kind of star power that might distract too much attention from the party's main campaign themes — Republicans are working to make the election a referendum on President Barack Obama — or overshadow the GOP presidential nominee himself.
Rubio, 40, is one such celebrity candidate. And the junior Florida senator also has little experience, in the midst of only his second year on Capitol Hill.
Still, Rubio is both a conservative favorite and potential bridge to the growing Hispanic voting bloc, which typically favors Democrats. He's a rising star within the Republican Party.
Ohio Sen. Rob Portman also is near the top of many speculative lists of potential running mates. Portman endorsed Romney early and campaigned hard for him in his home state. Romney, who won Ohio by a slim margin, knows Portman and is said to respect him.
The Ohio senator also is unlikely to spring any surprises on the Romney campaign. He's been confirmed to two Cabinet posts — he served as U.S. trade representative under President George H.W. Bush and then as Bush's director of the Office of Management and Budget.
Romney also is likely to consider conservative favorites talked about often, such as New Jersey Gov. Chris Christie, South Carolina Gov. Nikki Haley and Virginia Gov. Bob McDonnell. Still, if he's looking for experience, that group has just five years of gubernatorial experience among the three.
More experienced Republicans also are likely to be in the mix, and they could help Romney mitigate some political liabilities. Chief among those vulnerabilities is his wealth of as much as $250 million and his struggle to connect with working-class voters.
Former two-term Minnesota Gov. Tim Pawlenty comes from a working-class background that could help. He's been aggressively campaigning on Romney's behalf since suspending his presidential campaign last year.
GOP budget guru Paul Ryan, R-Wis., also came from humble beginnings. Ryan campaigned at Romney's side for several days ahead of Wisconsin's recent Republican primary, a victory that helped push Rick Santorum out of the race. It's unclear whether Ryan's role as face of the Congressional Republican budget plan, which includes a fundamental transformation of Medicare, would present too much political risk.
Over the coming months, the only thing that's certain in an otherwise uncertain process is that Palin's shadow — and the troubles of 2008 — will be looming large.
"There's one thing the people in the Republican establishment agree on: There was clearly not a thorough thought process or vetting that went into the vetting of Sarah Palin. They didn't ask the fundamental questions or spend enough time with her," said Sara Fagen, a former political director for President George W. Bush. "I don't think they're going to make the same mistake."
All told, the buzz about possible vice presidential nominees may be far larger than the actual difference the choice will make to voters.
An article in the New York Times noted: "There’s the supposed electoral weight some candidates bring: Mr. Rubio in Florida or Mr. Portman in Ohio. Yet over the past 40 years and 10 presidential elections, no running mate has made the difference in carrying a state."
This story is based on reporting by The Associated Press.