Cruz's aides and allies are preparing an aggressive effort to keep Marco Rubio from winning his home state of Florida on March 15, a blow they hope would render Rubio's path to the GOP nomination unimaginable and force him to withdraw.

A Rubio loss, Cruz's orbit believes, would then set up the two-man race with Donald Trump they believe they are destined for -- and absolutely need -- to win.

"Florida's a burning dumpster fire for Marco Rubio," said Cruz spokesman Ron Nehring. "If he doesn't win his own state, it's hard to rationalize going forward."

The strategy is not without risk: A Trump victory in Florida puts him 99 delegates closer to clinching the GOP nomination, weakening rivals' hopes of keeping him from reaching the delegate threshold and then defeating him at a brokered convention. And keeping Rubio from climbing is likely to cost millions of dollars.

A February poll showed Rubio 16 points ahead of Cruz, but 16 points behind Trump, who led the field in the Quinnipiac University survey at 48%.

Cruz is planning to spend part of next week in Florida, and in recent days his campaign opened 10 offices across the state. Under the direction of one of the aides who engineered his Iowa win, deputy Iowa state director Spence Rogers, Cruz has 300 county chairs and his campaign is preparing to unveil major endorsements and a list of Cuban-American supporters in coming days.

He shouldn't be short of cash. Cruz will attend a major fundraiser Monday in Houston, and the main pro-Cruz super PAC, Keep the Promise, unveiled a new big-money group Friday meant to draw in top donors. Keep the Promise is expected to advertise heavily in Florida.

With 10 media markets, Florida is one of the most expensive states in the country in which to advertise. Ten days out, the advertising war is frantic and escalating, as super PACs and campaigns empty their war chests on the first winner-take-all day on the GOP calendar. Paul Porter, a top Cruz fundraiser from Florida who helped set up Cruz's ground game in the state, said the race would now be dominated in part by negative advertisements.

Blake MacDiarmid, an unaligned Florida Republican strategist, said Team Cruz's overwhelming focus should be to "slice and dice" Rubio in Florida and make his home turf a "real Rubicon."

"Train your super PACs and your messaging on Rubio and keep him from getting up and winning," said MacDiarmid. "If you give him a little bit of Gatorade, the guy can make it happen."

Rubio's response

It would require an extraordinary turn in the race's momentum for Rubio to earn the 1,237 delegates to become the nominee. His team's most realistic path to victory relies on denying Trump that total and forcing a contested convention. Florida keeps that dream alive.

Rubio senior adviser Todd Harris said he would spend the "overwhelming majority of our time" between Saturday and the big day in his home state, scaling back his more ambitious hopes to compete in the other March 15 states. He again on Thursday pledged to win in Florida.

Rubio's super PAC, Conservative Solutions, has already poured $5.3 million into the state, much of which is being spent attacking Trump. Also joining in the cavalcade of anti-Trump forces are three unaligned outside groups: American Future Fund, Our Principles PAC and the Club for Growth, which together are on track to spend $3.5 million hitting him over the past week.

Some Rubio supporters take umbrage at what Cruz is trying to do, even as they crow that he will be unsuccessful. Ryan Wiggins, a Republican operative backing Rubio, predicted that Jeb Bush, who dropped out of the race three weeks ago, would beat Cruz in early voting.

"I think it's interesting that Ted Cruz would harm someone that is trying to help the party right now," said Wiggins, who thinks Cruz's strategy in Florida would make it difficult for anyone not named Donald Trump to be the nominee. "Politics is playing a long game, and that's a very, very shortsighted view of a long game."

And while Trump is leading, Rubio's team insists their private polling reveals a much closer race, and points to Rubio's stronger-than-expected performance in Virginia as evidence that their candidate will close strong. Rubio has consistently performed better than his polling numbers in key races this year, even if he has only won one state: Minnesota.

Rubio should not be surprised that Cruz is seeking to embarrass him: Rubio did the same to Cruz in Texas. Rubio's campaign and super PAC dedicated advertising money and candidate time in specific congressional districts to try to limit Cruz's haul on his home turf. (Cruz was held below the 50% needed to win all statewide delegates, but it had a cost for Rubio, who was held below 20% and walked away close to empty-handed.)

Trump attacks 'little Marco'

Meanwhile, Trump, who owns substantial property in Florida and considers the state a second home, is beginning to defend himself with his own paid media. Late Thursday, he began a series of advertising buys that came close to $2 million. His campaign declined to make its Florida state director available for an interview, but the candidate himself has pledged to win the state.

"You know that in Florida, they hate little Marco so much," Trump said in Michigan on Friday. "Maybe we'll be a little softer on little Marco. No?"

Despite Cruz's eagerness, some in Florida politics wonder if Cruz is arriving too late: His campaign or super PACs are not yet on the airwaves, while early voting expands statewide on Sunday, possibly numbering as many votes as those cast on Election Day.

Cruz aides and Florida leaders are making no bones about what is driving them — and it's not adoration for Trump.

"If the people who know you are rejecting you, it's time to get out," said Manny Roman, the vice chairman of the Miami-Dade GOP, who defected from Rubio to Cruz's leadership team.

Cruz, unlike Rubio, has declined to concede that he himself cannot reach the magic number of 1,237 delegates, an assumption that undergirds much of his Florida strategy. And his backers agree.

His campaign eyes March 15 as a pivot point in the race: a moment when a Rubio loss in Florida — perhaps combined with the defeat of John Kasich in his native Ohio — could end in a two-man race that Cruz says would allow him to take advantage of the high number of Republicans opposed to a Trump nomination. Even that path, though, would still require Cruz take a solid majority of the delegates between March 16 and the convention in June.

"If Trump wins Florida -- that gives him 99 -- and Rubio gets out and Sen. Cruz gets to go one-on-one, there's still enough time for Sen. Cruz to get the 1,237," said Porter. "And no deals are going to be made."