Sen. Marco Rubio (R-Fla.), left, campaigns with then-GOP presidential nominee Mitt Romney in Pennsylvania in 2012. (Mark Makela/Reuters)

The sun had not yet risen above the mountains here Friday when Marco Rubio gathered businessmen for an early game of flag football. In a T-shirt, shorts and sneakers, the Florida GOP senator played quarterback and wide receiver on the high-altitude field.

After the players returned for breakfast at a luxury lodge, Wisconsin Gov. Scott Walker cast the 2016 Republican race as a contest between ideological warriors who he called “fighters” and the “winners” who govern states — and argued he is the rare contender who is both. The night before, Walker regaled attendees of Mitt Romney’s annual summit in his private suite with an open bar, chips and guacamole.

Not to be outdone, Sen. Lindsey O. Graham plans to take guests skeet shooting Saturday. The South Carolina Republican, whose lifelong bachelorhood made headlines this week, also came armed with his impish humor.

“We tried tall, good lookin’, smart, nice, great family,” Graham told donors Friday in a playful nod to Romney. “Vote for me. We’re not going down that road again!”

Republicans have 10 declared candidates and counting, but they have no front-runner — not even the descendant of the closest thing the GOP has to a royal family. Former Florida governor Jeb Bush has struggled ahead of his official campaign launch on Monday, and he skipped the Romney confab because he was in Europe.

Wisconsin Gov. Scott Walker campaigns in New Hampshire in April. (Jabin Botsford/The Washington Post)

The fluidity gave the hopefuls who came — from top-tier favorites (Rubio and Walker) to dark horses (Ohio Gov. John Kasich and New Jersey Gov. Chris Christie) to long shots (Graham and former Silicon Valley executive Carly Fiorina) — an opening to court the business-friendly, establishment financiers who powered Romney to the nomination in 2012. Many of the donors are either helping multiple candidates or holding out until a likely winner emerges.

“The donors recognize it’s very easy for them to say, ‘I’m waiting, I don’t have to jump on board right now,’ ” said Spencer Zwick, Romney’s former national finance chairman who is uncommitted on 2016.

“No one knows how it’s going to play out,” said Ron Kaufman, a Romney confidant and fixture in Republican circles. “It’s different than any cycle we’ve ever been through before — and I’ve been doing this since Lincoln.”

Looming over the three-day retreat at the Stein Eriksen Lodge was Hillary Rodham Clinton, the dominant Democratic candidate, who will kick-start her presidential campaign with a rally Saturday in New York. In hotel hallways, on ski-slope hikes and in fire-pit huddles, leading Republicans pondered how to win — and acknowledged that Clinton cannot be underestimated.

“The candidates need to prove they can take her on,” said Tagg Romney, Mitt’s eldest son. “This thing is totally open. It’s so wide open. . . . It’s about seeing who emerges strongest.”

As they sat in rows with notepads and glasses of ice water, the GOP’s wealthy elite monitored how the speakers contrasted with Clinton. Kasich said Republicans must do more than “destroy” Clinton but also show heart and convince voters of the “kindness of conservatism.”

Rubio alluded to Clinton as “yesterday” and said he would usher in a new generation of leadership. “Some have said I should have waited my turn,” he said. “I didn’t know there was a line.”

Sen. Lindsey O. Graham (R-S.C.) racks pool balls during a campaign stop in Waterloo, Iowa, last week. (Daniel Acker/Bloomberg)

Graham was perhaps the most pointed, saying Clinton was eminently beatable — “She’s carrying more bags than any politician should” — but insisting that Republicans would have to soften their tone on immigration to break out of their “demographic death spiral.”

As Romney listened from the back of the ballroom, Graham, who backs a path to citizenship for undocumented immigrants, called attention to his host’s painful 2012 defeat.

“Hispanics, I think, are a great potential for the Republican Party, but nobody is going to vote for a party that’s going to break their family apart and deport their mother,” Graham said. “I love Mitt. That was the big mistake.”

Later, Romney thanked Graham for sharing his “wisdom.” His wife, Ann, told reporters: “He’s right. We’ve got to put a mirror up and see what’s going on.”

Despite Bush’s absence, plenty of his supporters were wooing possible millionaire backers. Kent Lucken, a Romney fundraiser and friend now helping Bush, was introducing the candidate’s son, Jeb Jr., to the Romney crew, while Bush ally Ana Navarro worked the cocktail circuit. “The media narrative and the reality are disconnected,” Navarro said.

But there was noticeable energy around some of the younger candidates.

“The Republicans send a huge message if they put a Walker-Rubio ticket together — and I want Walker’s name first,” said Anthony Scaramucci, a prominent investor. “It would say, ‘We’re ready to break our establishmentarian baton-passing.’ ”

Walker strategist Rick Wiley chatted late into the night Thursday around a mountainside fire pit with mega-donor Todd Ricketts, who directs his billionaire family’s political spending and plans to boost Walker. Romney hands hovered nearby, grading the candidates over wine.

“A lot of people were impressed with Rubio. They liked Walker’s low-key style and thought Kasich was very blunt,” said Lanhee Chen, Romney’s former policy director. “But there wasn’t any significant movement toward any one candidate. It’s still anyone’s game.”

Christie shrugged off his poor standing and said debates could revive his chances. “You know what matters?” he said defiantly. “Performance matters.”

Organizers strived to maintain an aura of exclusivity. Media access was tightly controlled, with journalists requiring escorts to roam the premises and photography prohibited. When fundraiser Wayne Berman waved over reporters who were stuck behind a rope line, he quipped, “We’re not in Cuba!”

Still, the high-finance feel of the conclave was vintage Romney. He drew laughs Friday when he misidentified Berman, a senior adviser at Stephen A. Schwarzman’s Blackstone Group, as working at a rival firm.

“What did I say, ‘KKR’?” Romney said. “Blackstone. Oh, boy, I’m in trouble now. Steve Schwarzman is going to shoot me.”