Jeb Bush greets Marco Rubio at the soon-to-be-senator’s election-night victory party in 2011 in Coral Gables, Fla. (Joe Raedle/Getty Images)

Dan Britton is in many ways the quintessential Jeb Bush voter — a staunch Republican who spends his days whizzing a golf cart around this huge Florida retirement community that once served as a critical support base for Bush’s statewide campaigns.

But ask Britton about the former governor’s presidential campaign and he shakes his head. Like many residents here, Britton moved to the state years after Bush left office.

“He was governor a long time ago,” said Britton, a retired builder and architect who moved here two years ago from Connecticut. Instead, Britton has his eyes on Florida’s current GOP star, Sen. Marco Rubio. “He’s young. He’ll help with the Hispanic vote. I like what he says.”

In a Republican field dominated by surging political outsiders, the battle over who should carry the mantle of the GOP establishment is, at this moment, shaping up as a duel between the former allies who are now Florida’s two political powerhouses.

As other establishment contenders, such as Ohio Gov. John Kasich and New Jersey Gov. Chris Christie, are lagging in fundraising and in polls, Bush, 62, and Rubio, 44, each see the other as his chief rival — with the survivor best positioned to wrest the nomination from party outsiders, mainly Donald Trump.

How much money is behind each campaign?

The tensions between the two sides hit a new high this week as Rubio’s campaign bragged that its “smart budgeting and fiscal discipline” left more money in the bank “than Jeb Bush for President” and other campaigns. Bush’s top spokesman fired back Friday on Twitter, pointing to a report that said Rubio’s campaign inflated its numbers and adding a stinging rebuke: “Lying about budgets. Guess Marco picked up something in the Senate.”

Heightening the drama of this once unthinkable showdown between mentor and protege is that it may be decided in Florida, the state that elected Bush twice as its chief executive and propelled Rubio from small-town city commissioner to state lawmaker to U.S. senator.

With the huge prize of 99 delegates in its winner-take-all primary and the timing of the state’s March 15 vote, many Republicans see Florida as the critical contest that will winnow the crowded GOP field. A defeat at home would be a humiliating — if not lethal — for Bush or Rubio. Recent polls have shown the two neck and neck in the state, though far behind Trump and, in some surveys, retired neurosurgeon Ben Carson.

Much of the state’s Republican establishment is backing Bush, who has rolled out lists of elected officials endorsing him, including 20 of the 26 Republican state senators. Bush has also far outpaced Rubio in donor support, nationally and in Florida.

Others are avoiding publicly declaring their preference. Both candidates are rebuilding and expanding their networks across the state. Bush has a bigger ground operation, and his national headquarters is in Miami. Rubio, who has focused more of his time building name recognition in other early-voting states, is preparing to announce chairs in all 67 Florida counties.

“Right now it’s a tossup between Bush and Rubio,” said Don Hahnfeldt, a county commissioner who lives in The Villages and is running for the state legislature.

What’s coming in Florida, said Republican strategist Kellyanne Conway, who is backing Sen. Ted Cruz (R-Tex.), is “the most significant, Armageddon-like battle of the Republican primary.”

Welcome to The Villages

There are few better barometers of the Florida Republican primary race than The Villages, a community an hour northwest of Orlando sometimes called “Disneyland for retirees.” It’s a place where people drive golf carts to the Winn-Dixie for groceries and to the town squares to hear live music each night.

The 114,000 residents — many of them affluent, and many of whom ran companies, managed offices or served in the military — are overwhelmingly Republican.

Voter turnout is higher than anywhere in the state. Bush and Rubio were regular visitors in the past — Bush dedicated the community’s charter middle school as governor — and locals expect to see more of them ahead of the primary. Rubio came through last month and offered some not-so-subtle digs at Bush, telling an overflow crowd at the Eisenhower Recreation Center that the GOP and the country needs to elect a “new generation of leaders with ideas relevant to the times in which we live.”

The Villages, full of people who have moved from other states, also underscores the challenges Bush and Rubio confront in Florida, despite their advantages as the home-grown presidential candidates.

The state’s ballooning population in recent years — it recently surpassed New York as the third-largest state — means that many voters have no particular allegiance to either candidate. In fact, in dozens of interviews here, many said they were more familiar with Trump, the ubiquitous billionaire and reality-television personality who also has a home in Palm Beach. In The Villages, which adds new people every day, half of the residents didn’t live here in 2010.

“Insiders are sticking with Bush, but a lot of regular, everyday voters have no strong bond,” said Brad Coker, who is managing director of Mason-Dixon Polling and Research and has years of experience measuring public opinion in the state.

One of the most active conservatives in The Villages, for instance, Aileen Milton, founded her tea party group only in 2012.

Milton, whose group has 300 dues-paying members, said she is impressed with Rubio on foreign policy. And she is no fan of Bush, particularly after he said that many immigrants cross the border illegally as an “act of love” for their families.

“Honestly, he sounded naive and gullible,” Milton said.

Bush, who at every campaign stop talks about his Florida record of cutting taxes and creating jobs, has made frequent appearances in the state.

He and his supporters are now challenging Rubio more directly, suggesting that he lacks experience and ridiculing his frequent absences from the Senate.

To highlight that Rubio has missed more votes than any senator, Bush is proposing that members of Congress who miss votes should have their pay docked. This week, Bush’s son Jeb Jr., noting Rubio’s absences, told college students in New York that Rubio should “either drop out or do something,” according to a Politico account of the event. Jeb Jr. also said that his father’s campaign was “way ahead” of Rubio’s in Florida.

Bush has poked at Rubio’s experience, portraying the senator as a follower in his past efforts to enact reforms in the state. Bush told CNN recently that as governor, “I relied on people like Marco Rubio and many others to follow my leadership.”

Bush is also hurling perhaps the most toxic insult that one Republican can give to another: He says Rubio is like Barack Obama — a one-term senator running for president.

“Look, we had a president who came in and said the same kind of thing — new and improved, hope and change — and he didn’t have the leadership skills to fix things,” Bush said on CNN.

Ray Wescott is listening. As the former restaurant owner from Baltimore County sipped a vodka tonic in his usual spot, a table overlooking the ninth green at the Hacienda Hills Country Club here, he recalled fondly how Bush cut taxes while leading the state from 1999 to 2007.

“Jeb Bush did a hell of a job as a governor,” he said.

Bush’s record resonates with others in The Villages, too.

“Yes, I would vote for Bush because I saw him balance the budget,” said Al Monteleone, 72, one of the morning regulars at Dunkin’ Donuts and a longtime Florida resident. “My wife is a teacher, and he was good on education, too.”

But more here say the main thing they know about Bush is that he is the brother and son of presidents. “Bush?” said Britton, the transplant from Connecticut. “People are tired of status quo, and Bush equals dynasty.”

Many said Rubio is generating more buzz.

‘A young John Kennedy’

During his visit here last month, Rubio talked to the retirees about the challenges of a fast-changing world, throwing in references to Uber, Airbnb and Candy Crush as he presented himself as the leader of a new generation.

“He is young, personable, smart, eloquent,” said Rusty Blankenship, a retired state trooper from West Virginia who attended Rubio’s speech. “I guess it’s not quite right to say this, because he is a Republican, but he reminds me of a young John Kennedy.”

Blankenship first got interested in Rubio just a few weeks ago. After watching the second Republican debate last month at the Ronald Reagan Presidential Library in Simi Valley, Calif., he went online to learn more about Rubio, signed up for “Team Marco” to get more information, and even sent a donation.

Henry Berg, 81, said that after watching the two GOP debates, he preferred Rubio, the “young guy.”

He said Bush had been “a good governor.” And he couldn’t point to anything in Rubio’s record. Still, he was going with a gut feeling: “I just like him.”

Sean Sullivan, Anu Narayanswamy and Jose DelReal in Washington contributed to this report.