Republican presidential candidate Marco Rubio addressed supporters in Miami, Fla., on Super Tuesday. (Reuters)

Bruised by a string of Super Tuesday losses, Marco Rubio is desperately fighting to win the Florida Republican primary in two weeks to save both his presidential campaign and his political future.

Florida and its 99 delegates are Rubio’s last best hope to at least slow Donald Trump’s path to the nomination by accumulating delegates that would otherwise go to the front-runner. Given his big lead, Trump can afford to lose Florida on March 15 — but he’s clearly eager to humiliate Rubio on his home turf.

The billionaire businessman is ahead by a double-digit margin in Florida, leading by 44 percent to 28 percent in a Quinnipiac University poll of likely Republican primary voters released last week. Trump plans to campaign hard across a state where he is well known for his luxury resorts and golf courses — and where he is already using his well-known methods of attack.

Rubio told thousands of supporters in a city park here Tuesday night that Trump’s support is slipping because he has started “to unmask the true nature of the front-runner.”

“We are going to send a message that the party of Lincoln and Reagan — and the presidency of the United States — will never be held by a con artist,” he said.

Alex Burgos, Rubio’s Florida spokesman, said the campaign has “only begun to expose this guy for the fraud that he is. In Florida, people know who con artists are. Here, you either have been the victim of a con artist or know someone who has been. This is a state riddled with con artists, and unfortunately, now one of them is running for president.”

But with Rubio trailing Trump so badly, some supporters wonder why the senator didn’t attack sooner.

“He just waited too long,” said Robert Matos, a local resident. “I will vote for Trump if that’s the only choice I have, but I would rather vote for Rubio.”

Other prominent Florida Republicans are withholding support for Rubio, most notably former governor Jeb Bush, who abandoned his own presidential bid last month. A spokeswoman said Bush has no plan to back his former protege.

Bush and Rubio played out a Shakespearean-style tragedy for Florida Republicans last year by launching rival campaigns that splintered their political support. With Bush out of the race, many Rubio supporters and campaign observers expected that the governor’s donors and active supporters would quickly switch allegiance to the senator. But that hasn’t happened.

“There’s a lot of people that are going to wait for Governor Bush before they do anything, both monetarily and with their personal support,” said Will Weatherford, a former Florida House speaker who supported Bush before endorsing Rubio. “There’s no question that a Jeb Bush endorsement in Florida goes a long way.”

Rubio has recruited some of Bush’s former fundraising bundlers, but others are holding out. In most cases, they doubt Rubio will prevail and don’t want to spend more time and money fighting an opponent they’ve already failed to stop.

“If you don’t see a donor rush, it’s because people are seeing what I’m seeing: Show me how Trump can be beaten,” said Al Cardenas, a Miami-based lobbyist and conservative activist who is a longtime Bush friend and former Rubio employer.

For now, Cardenas said, “I’m off the grid. I put my heart and soul into helping Jeb and I’m just not ready to get back into this thing anytime soon. I might. I’m just not making that decision today.”

Bill Kunkler, a Chicago-based private-equity executive who helped raise millions for Bush, said Rubio “has got no record. There’s nothing there in his record,” and so he will be “sitting it out. . . . I’m just not going to waste my time and come up short.”

Rubio has also failed to unite the Florida Republican Party behind him. Gov. Rick Scott has been mulling a Trump endorsement — a move that would be seen as a high-profile rejection of his home-state senator.

Even so, Rubio does have the backing of more than 80 current and former Republican officials in the state, including dozens who once backed Bush, such as Miami-area GOP lawmakers Carlos Curbelo, Ileana Ros-Lehtinen and Mario Diaz-Balart.

In Florida, Trump’s name adorns several affluent properties along the Miami coastline, and his Mar-a-Lago resort in Palm Beach has become a fixture among Florida’s upper crust. In Miami, Trump’s National Doral Club — one of three golf clubs he has in the state — hosts a PGA golf tournament each year.

“Why would anyone in Florida vote for lightweight Senator Marco Rubio,” Trump asked on Twitter on Wednesday. “Check out his credit card scam, his house sale & his no show voting!”

Those are references to well-documented aspects of Rubio’s past. He reimbursed the Florida GOP after improperly using a party charge card to cover personal expenses. He purchased a Tallahassee home with David Rivera, a former colleague in Florida’s House of Representatives, and they sold it for far less than they had bought it. His worst-in-the-Senate attendance record is also a familiar line of attack.

Trump campaign officials did not respond to requests for information on the size or cost of their operation in the state. But Trump is easily dominating television and radio newscasts: On Tuesday night, TV networks aired Trump’s press conference from the Mar-a-Lago resort while mostly ignoring Rubio’s Miami rally.

Rubio campaign staffers are working out of offices in Miami, Boca Raton, Orlando, Tampa and Jacksonville. Clint Reed, who ran Rubio’s campaign in Iowa, is now running Florida operations from the Orlando office while senior aides run the campaign from the Washington area.

One serious problem for Rubio is money: His campaign had only about $5.1 million as of Feb. 1 — not nearly enough to run an effective statewide ad campaign across the state’s 10 media markets.

Adam Hasner, co-chairman of Rubio’s campaign, said that they will need to rely on outside help.

“There’s probably people who I don’t talk to who are going to be very involved,” he said, referring to Conservative Solutions PAC, a group that is already airing TV ads in the Miami and Tampa markets. By law, the Rubio campaign cannot coordinate with the group.

The PAC has spent roughly $7.5 million in Florida as of Wednesday, most of it opposing Trump, and all the spending has come in the past week. Spanish-language ads are airing in South Florida.

Other political groups, including the American Future Fund and the Club for Growth, are also poised to spend millions of dollars attacking Trump in TV ads.

Whether such attacks will work remains unclear. Rep. John Mica (R-Fla.) represents a swath of Central Florida and predicted last week that Trump will win 40 to 45 percent of his congressional district. “Cruz will be very strong and then probably Rubio third,” he said.

And what happens if Rubio loses Florida?

“At that stage, people have got to be looking at who’s going to be vice president,” Mica said.

DelReal reported from Louisville. Scott Clement, Mike DeBonis and Anu Narayanswamy in Washington contributed to this report.