FRANKENMUTH, Mich. - Mitt Romney's vice presidential search team is not seriously vetting Sen. Marco Rubio (Fla.), one of the Republican Party's brightest young stars, as the all-but-certain GOP nominee increasingly gravitates toward more experienced but less charismatic leaders as a potential running mate.
ABC News first reported Tuesday morning that Romney's campaign had not asked Rubio to complete a questionnaire or submit any personal financial documents, which one outside Romney adviser confirmed to The Washington Post on Tuesday. The adviser left open the possibility that Romney officials could decide to thoroughly vet Rubio at a later date.
Another Romney adviser who works directly on the campaign said that Romney officials conducted a preliminary review of Rubio, mostly reviewing documents, statements and news reports that are publicly available. The team did a similar public vetting with a large number of other candidates before whittling down to a short list for a more thorough investigation.
Other vice presidential candidates, including Sen. Rob Portman (Ohio) and former Minnesota governor Tim Pawlenty, are undergoing a more intensive review, according to two Republicans close to the campaign.
Romney campaign spokespeople, as well as top aides to Rubio, declined to comment on the vice presidential candidate search, which has been underway for two months.
Although many of the party's grass-roots conservative activists favor Rubio - he routinely wins vice presidential straw polls - Romney has long said that his top priority in selecting a running mate is finding a partner with the experience and wisdom to step in as president on day one.
Romney said Monday that he would not base his decision on a candidate's popularity among conservatives but on the person's readiness for high office. "Obviously the decision will be made by me on a very different basis," he told the Des Moines Register. "My criteria is who can be president if that were necessary."
Romney regularly talks about Rubio in his stump speeches, and last Friday used the senator's statement on President Obama's new immigration policy as a starting point for his own views on the subject. Yet throughout the spring, some of Romney's advisers tried to tamp down speculation that Rubio was a favored pick for vice president.
"By the time you apply the gravitas test, which is really 95 percent of what Governor Romney's looking at - people when introduced to America nobody would think twice about their ability to be president if necessary - that wipes out 90 percent of the field," said one outside adviser close to the Romney operation who requested anonymity to speak candidly about the selection process.
The adviser said other Republicans once presumed to be contenders, including Sen. Kelly Ayotte (N.H.) and New Mexico Gov. Susana Martinez, fall under this same category. More-experienced candidates said to be under consideration include Rep. Paul Ryan, the House Budget Committee chairman, as well as Louisiana Gov. Bobby Jindal.
Romney, who was vetted by John McCain in 2008 but lost out to then-Alaska Gov. Sarah Palin, has told confidants that he does not want to put a candidate through an intensive vetting process unless he is legitimately considering him or her for the job.
"It's a decision that's going to be made by basically one person, and there's a lot of data gathering going on to put those choices out in front of that person," said one senior adviser to Romney who requested anonymity to speak about the process. "It's going to be orderly. and it won't happen, I don't think, before July 4th. But they're ready."
Rubio, 41, was elected to the Senate in 2010 after having served as speaker of the Florida House of Representatives. The eloquent Cuban American was an instant star in the tea party movement and arrived in Washington with heady expectations.
"Blue skies ahead," the outside Romney adviser said of Rubio. "But could he be president tomorrow? I don't think so."
Even as his political mentor, former Florida governor Jeb Bush, said Rubio was his pick for vice president, Rubio routinely tried to insist that he had no interest in joining the national ticket.
In late March, when he announced his endorsement of Romney, Rubio told Fox News: "I don't believe I'm going to be asked to be the vice presidential nominee. That's not what I intend to be, that's not what I want to be and that's not what is going to happen."
Still, by looking past Rubio, Romney risks angering Latinos and conservative activists who had hoped to see the young star on the ticket. Ana Navarro, who advised McCain on Hispanic issues in the 2008 race and is close with Rubio and Jeb Bush, said, "it's very strange that it would be true."
"What does Romney have to gain from the rumor being out there that Rubio is not being vetted?" she said. "Rubio is a guy who consistently comes out on top of Republican base polls. . . . It benefits Romney to have Rubio out there beating the drums for him, being a strong surrogate, fundraising for him, and campaigning his heart out."
Portman, Pawlenty and Ryan have far more active on the campaign trail on Romney's behalf than Rubio. Pawlenty spent two days traveling with Romney on his campaign bus last weekend, through New Hampshire and Pennsylvania, while Portman and his wife spent Sunday with Romney and his wife, Ann, as they campaigned across Ohio. And Ryan joined Romney on Monday in Wisconsin.
Ryan and Portman are scheduled to host a Romney fundraiser next week in Washington, targeting young professionals, while Pawlenty regularly represents Romney on political talk shows and finance events.
Their work on Romney's behalf has been noted by Romney's advisers; one of them labeled Pawlenty "an incredible warrior." The former Minnesota governor, who was runner-up in McCain's veepstakes, has emerged as a favorite among some of Romney's staffers because he is loyal to Romney, consistently on-message and has so few airs about him. On the campaign bus this weekend, he chatted with staffers about rock music.
But many Republicans close to Romney consider Portman to be the front-runner for the nod. The outside adviser to Romney said that as Romney's team looks deeper into Portman, they find more appeal - including, the source added, that Portman speaks fluent Spanish.
"Anybody that scratches the surface a little bit on Portman starts liking him more and more the deeper they go," the source said.
Rubio has far less of an established relationship with Romney. The two have campaigned together just once, in Pennsylvania in April. Rubio has paid more attention to nurturing his own political pursuits. This month, Rubio will be busy promoting his new memoir, with a book tour planned through several key presidential voting states.
Along his five-day bus tour, Romney said he has been hearing a lot of advice from supporters at the rope lines of his rallies regarding who he should pick.
"In Wisconsin, I get a lot of people saying, 'Paul Ryan ought to be your VP,'" Romney said. "When I'm in Ohio, I get, 'Rob Portman, he ought to . . . .' "