Sheldon Adelson, one of the Republican Party's most sought-after contributors, is leaning increasingly toward supporting Marco Rubio — and the Florida senator is racing to win the backing of other uncommitted megadonors who have the potential to direct tens of millions of dollars his way and alter the contours of the Republican primary fight.

Last week, during a campaign swing through Las Vegas, Rubio held a meeting in Adelson's offices at the Venetian Las Vegas, one of a number of five-star luxury casinos the billionaire mogul owns around the world. Adelson, seated at the head of his conference table, heaped praise on Rubio’s performance while he discussed the dynamics of the 2016 race. Those briefed on the meeting described it as short but said it had an air of importance, with the two joined by Rubio’s campaign manager, Terry Sullivan, and a pair of senior Adelson advisers, Rob Goldstein and Patrick Dumont.


Those close to Adelson — who spent more than $100 million on Republican candidates and causes during the 2012 campaign and has been aggressively courted by most would-be Republican nominees — stressed that the 82-year-old gambling magnate had made no final decision on whom he’d support but said that momentum had strongly shifted to the Florida senator. A formal endorsement, they said, could come as soon as the end of the month — and with it, the potential for a multimillion dollar contribution. With a net worth of $25.7 billion, according to Forbes, Adelson can afford to spend freely.

The news of Adelson's growing affinity for Rubio comes as the Florida senator has seen his poll numbers climb in recent weeks — support his campaign is hoping to translate into cash. “I think it’s obvious that Marco is gaining some strength,” said Anthony Gioia, a retired ambassador and top Rubio fundraiser. “The more people hear him, the more strength he seems to be getting.”

Rubio and Adelson have grown increasingly close, with the senator phoning the billionaire several times a month to provide in-depth updates on the state of his campaign. The two men also have detailed policy discussions, especially about international affairs and Israel — the latter a cause near and dear to the mogul. Adelson has long looked favorably on Rubio, a fellow son of immigrants. Two people familiar with his thinking said he has become increasingly confident in the senator’s political skills and believes he is the kind of fresh face the Republican Party needs in 2016. (An Adelson spokesman declined to comment.)

Adelson is just one of several GOP megadonors visited in recent days and weeks by Rubio, whose months-long courtship of deep-pocketed benefactors is taking on a new intensity.

Last week, Rubio also held a lengthy private meeting in New York City with Paul Singer, a hedge fund manager who is among the most prolific Republican donors in the country but who has yet to pick a favorite. During a gathering of Rubio donors in Las Vegas last week, attendees were abuzz about the possibility of bringing aboard Singer. (A Singer side said he “hasn’t made a decision on the presidential election yet.”)

Charles Schwab, a powerful investor who has also remained on the sidelines, has privately expressed interest in Rubio's candidacy. Those close to the senator say he’s been wooing the 78-year-old Schwab, whose net worth is an estimated $6.4 billion, for weeks. At the Las Vegas retreat, attendees circulated a list of top donor targets, with Schwab high up on the list. (Schwab's spokespeople did not respond to requests for comment.)

In recent days, Rubio has also been courting the Ricketts family, which own the Chicago Cubs and gave more than $5 million to a super PAC supporting Scott Walker before the Wisconsin governor suspended his campaign.

A Rubio spokesman, Alex Conant, declined to comment on his talks with prospective donors.

But winning over such coveted backers would provide a major boost to Rubio's campaign — and deliver a blow to Jeb Bush, who has been counting on his considerable financial advantage to carry him in the primary contest. (At the close of the second fundraising quarter, Bush and the outside groups supporting his candidacy reported raising over $100 million, more than twice as much as Rubio.) It would also bolster the Florida senator after a lackluster third quarter in which his campaign raised just $6 million, though aides say he has a substantial amount of cash on hand.

For presidential contenders, Adelson and Singer are especially prized because they lay claim to broad networks of political donors who will follow their lead. Last week, Singer convened a group of powerful contributors in New York City for a two-day gathering to discuss the political landscape. Adelson, meanwhile, sits on the board of the Republican Jewish Coalition and each spring hosts a gathering for the group at his posh Venetian hotel.

But both men have remained on the sidelines this year, awaiting greater clarity in a crowded and rambunctious primary, like many other top GOP donors. Rather than committing to Bush — long expected to be the Republican front-runner — they are taking stock of their power and keeping one another apprised of their considerations. Representatives for a number of wealthy Republican benefactors — including Adelson, Charles and David Koch, and the Ricketts family — recently gathered in New York City to discuss how the race is shaping up.

The Kochs are not expected to endorse a single candidate but rather to wait out the primary. Yet as Rubio supporters gathered in Las Vegas last week, many were surprised to see a top Koch official, Phillip Ellender, in attendance.

In an email, Ellender, who heads up the Kochs' government and public relations division, said his attendance at the event, and support for Rubio, is independent of “the company I am privileged to work for.”

Not all the powerful Republican donors Rubio is wooing, however, are sold on him.

Next week, he will meet with Doug Deason, the son of billionaire megadonor Darwin Deason. Three weeks ago, the younger Deason, who had supported Rick Perry before he dropped out last month, sat down with Rubio in Texas. While Rubio sipped a ginger ale, the donor brought up the senator’s recent statement in support of federal sugar subsidies — a position Deason said he disagreed with.

In an interview, Deason recalled getting an unsatisfactory answer from Rubio and said he hoped to get a better response the next time they met. In the meantime, he said, he is scheduling meetings with several other candidates, including Bush and Ben Carson.

“I like him a lot,” Deason said of Rubio. “But we’re on the fence currently.”