In this 2012 file photo, Sen. Marco Rubio, left, listens as Republican presidential candidate Mitt Romney speaks in Aston, Pa. (Jae C. Hong/AP)

Sen. Marco Rubio has been cultivating a relationship with Mitt Romney and his intimates, landing some of the 2012 Republican nominee’s top advisers and donors and persistently courting others as he readies an expected 2016 presidential campaign.

In a crowded field of contenders, the imprimatur of Romney could help clear Rubio’s path into the top tier. Since Romney announced in January that he would not run for the White House again, he and Rubio have had at least two lengthy phone calls in which Romney encouraged and mentored the 43-year-old Florida senator about the political landscape, according to a Romney associate.

[ Rubio is the ‘upside’ candidate of 2016 ]

Rubio and Romney have built a warm and trusting rapport, in contrast to the frostiness that exists between Romney and the two current GOP front-runners, former Florida governor Jeb Bush and Wisconsin Gov. Scott Walker. When Romney said in January that it was time to turn to the “next generation of Republican leaders,” it was widely interpreted as a swipe at Bush and a boost to a fresher face, such as Rubio.

In one-on-one meetings and communications with members of Romney’s inner circle, Rubio has impressed them with what they see as his compelling personal story, his depth and positions on policies, and his respect for Romney and his legacy in the Republican Party.

Sen. Marco Rubio, who's running for president in 2016, is known for his stances on immigration and tax reform. Here's the Florida Republican's take on Obamacare, the Islamic State and more, in his own words. (Julie Percha/The Washington Post)

[ April 13: Rubio tells supporters he’s running ]

For Rubio, winning over key elements of the Romney ­coalition could give him a stronger foundation for a competitive campaign. But the support from Romney’s team alone would not guarantee Rubio success against Bush’s well-funded juggernaut or Walker’s grass-roots appeal.

Rubio has signed up two prominent former Romney officials in recent weeks. Rich Beeson, Romney’s 2012 national political director, has been tapped as Rubio’s likely deputy campaign manager, while Jim Merrill, Romney’s longtime New Hampshire strategist, is on board to play the same role for Rubio.

“For me, his substance, his skill and his story really stuck out,” Merrill said. “I always said if Mitt had decided to run again, I’d be with him. But when he decided not to go, I took a careful look at the field, and Marco represents the next generation of Republican leadership.”

Rubio’s courtship has been particularly intense with Spencer Zwick, who served as national finance chairman of Romney’s $1 billion campaign and is seen as the keeper of the Romney flame. Zwick said in an interview that the senator solicits advice from him regularly in phone calls, e-mails and text messages.

Rubio asks Zwick about how to assemble a campaign infrastructure and win the nomination, about lessons learned from Romney’s 2012 loss. Both fathers of young children, the two men talk about their families, too.

Zwick said he remains unaffiliated in the 2016 sweepstakes, but heaped praise on Rubio.

“Have you watched him speak?” Zwick asked. “This guy gives a message about the American dream that is compelling. People can say, ‘Oh, it’s the same speech every time,’ but you know what? Ronald Reagan did that, too, and it happened to work.”

Zwick called Rubio “an astute politician and a genuine person,” saying he “is universally well-liked by donors.”

Still, Bush has established himself early as the 2016 field’s fundraising dynamo, signing up many of Romney’s biggest bundlers, especially in New York and Florida, where he threatens to squeeze Rubio out.

A handful of former senior Romney aides and advisers have fanned out to work for an array of likely candidates besides Rubio, including Bush, Walker, former Texas governor Rick Perry, New Jersey Gov. Chris Christie and Louisiana Gov. Bobby Jindal.

The biggest Romney fundraiser helping Rubio is Wayne Berman, a fixture in GOP fundraising circles and a co-chairman of Romney’s 2012 national finance committee. Many Romney loyalists — including friends and associates from Bain Capital, the Mormon Church or the Salt Lake City Olympics — have stayed unaffiliated and are looking for signals of Romney’s preference.

Romney is unlikely to endorse a candidate anytime soon and has invited most of the GOP 2016 field to his annual policy summit with top donors and business leaders in June in Park City, Utah, where Romney has a home.

Rubio also has roots in the Mountain West. Although he was born into the Catholic Church, Rubio lived for several years of his childhood in Las Vegas and, during that time, was baptized in the Mormon Church. In his teen years, he and his family returned to Florida and rejoined the Catholic Church, although many of Rubio’s cousins remain affiliated with the Church of Jesus Christ of Latter-day Saints.

Some Romney loyalists harbor bad feelings about several candidates. Privately, they say Bush was not as active in his support as they expected in 2012 and that they think he tried to muscle Romney out of the 2016 race in January.

They hold a grudge against Walker for sharply criticizing Romney in his 2013 book, “Unintimidated,” for doing “a lousy job” connecting with voters. And many Romney insiders were steamed at Christie for his high-profile embrace of President Obama, after Hurricane Sandy devastated the Jersey Shore in the final week of the campaign.

By contrast, Romney’s allies almost universally praise Rubio, who was vetted as a possible vice-presidential pick and worked on Romney’s behalf during the campaign. They singled out his prime-time speech — introducing Romney — at the 2012 Republican National Convention in Tampa.

“He was an exceptional surrogate,” said Matt Waldrip, a former Romney finance aide and Zwick associate. “When he went to events, people showed up. He packed the house, whether fundraising or otherwise. He did whatever we asked him to,
clearly interested in helping the cause and helping the ticket.”

On Tuesday, Rubio met at the Russell Senate Office Building in Washington for an hour with Lanhee Chen, Romney’s former policy director, who remains an adviser and friend. Chen said he was impressed by Rubio’s preparation for the meeting, which focused on foreign and domestic policy, as well as his depth on the issues.

“Senator Rubio has spent the last several years developing thoughtful conservative policy solutions, and he has a personal story that makes those solutions even more compelling,” Chen said.

Rubio’s camp has been in touch with other Romney associates, including Peter Flaherty, a former Boston prosecutor who for years was Romney’s chief liaison to conservative movement leaders. Those talks have been informal, and Flaherty, like Chen and Zwick, remains uncommitted to a 2016 candidate.

“It’s elbow grease,” said one Romney confidant who spoke on the condition of anonymity to talk candidly about Rubio’s outreach. “Marco’s actually picking up the phone and calling people, saying, ‘Listen, I want to introduce myself and tell you who I am and what I stand for.’ It’s good politics.”

Terry Sullivan — who ran Romney’s South Carolina primary campaign in 2008 and for years has been a top Rubio adviser — has been helping him facilitate his outreach into Romney’s world. Sullivan is executive director of Rubio’s Reclaim America PAC and is his likely campaign manager. Rubio’s Senate chief of staff, Alberto Martinez, was a Florida-based adviser to Romney’s campaign in 2012.

Rubio is expected to formally launch his presidential bid next month, although aides stressed this week that no final decision has been made on the timing or venue. His advisers are preparing for a long and steady race, with a focus on laying the groundwork in the early-voting states.

Although he has been overshadowed recently by Bush and Walker, Rubio has generated some buzz among Republican insiders. His speeches at recent donor conclaves, including at the Club for Growth last month in Palm Beach, Fla., drew rave reviews.

Rubio has said he can raise the funds needed to mount a serious presidential bid. Norman Braman, a billionaire South Florida auto dealer, is expected to donate as much as $10 million to Rubio and his anticipated super PAC.

Rubio has his own national donor network, which he began cultivating in his upstart 2010 Senate campaign. The group includes donors who participate in the political network organized by industrialists Charles and David Koch, whose California meeting Rubio addressed in January.

But Rubio is making inroads elsewhere, too. He dined alone last week in Washington with Sheldon Adelson, the billionaire Las Vegas casino magnate who spent tens of millions of dollars trying to elect Romney in 2012.

Sen. Roy Blunt (R-Mo.), who was Romney’s liaison on Capitol Hill in 2012, recently explained why so many Republican insiders find Rubio appealing.

“I often have a vision of Marco in the cloakroom of the Senate, when not much is going on, trying to watch his son’s football games on his smartphone,” he said.

Blunt then used a descriptor that few would have applied to Romney: “humanizing.”

Ed O’Keefe contributed to this report.

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