The increasingly desperate effort from the Republican establishment to stop Donald Trump’s presidential campaign ran aground again Tuesday, this time by betting big on Marco Rubio winning Florida.

Three anti-Trump groups—Our Principles, American Future Fund, and Club for Growth Action—funneled millions in television ads to attack Trump in Florida, a decision that left the Republican establishment's fight against him in Illinois, North Carolina, and Missouri largely to the campaigns and affiliated super-PACs. 

The result was devastating. Trump scored his biggest state win of the nomination race so far—collecting all 99 of Florida's delegates—and Rubio dropped out of the race. 

Katie Packer Gage, a founder of the Our Principles, said the group “staked out Florida because it looked like it needed more help.” Despite buying two-and-a-half times as many ads in Florida as in Illinois, Missouri, and Ohio combined, it was not enough.

Trump also expanded his lead with narrower wins in Illinois and North Carolina. He was in a virtual tie in Missouri, a race the Associated Press said was too close to call. Ohio, the fifth state up for grabs on Tuesday, went to Governor John Kasich, who now counts his home state as his single victory in nearly three dozen nominating contests so far.

Andre Tartar/Bloomberg

Mission Impossible

The decision to focus on Florida, where public opinion polls consistently showed Rubio down by 20 percentage points, rankled supporters of Senator Ted Cruz, who has proven to be Trump's closest competitor throughout the nomination race.

“It was a thinly disguised pro-Rubio effort,” Kellyanne Conway, a top strategist for the super-PACs backing Cruz, said about the anti-Trump effort in an interview Tuesday. “The anti-Trump effort, part of it will have to become a pro-Cruz effort. It has to. Otherwise it doesn’t work.”

The three groups aired 8,100 ads on broadcast television in Florida during the past week, according to CMAG/Kantar Media. In Illinois, where Cruz was almost 9 points behind Trump, they aired about one-fifth of their Florida onslaught. In North Carolina, where Cruz finished 3 percentage points behind Trump, not a single ad was purchased.

“Our goal was always to win both Florida and Ohio. Those were our top two priorities,” said Packer Gage. “Those are winner-take-all. We wanted to deprive Donald Trump of the two big winner-take-all states.”

Trump, speaking at his Mar-A-Lago resort in Palm Beach, Florida, on Tuesday, made sure to note that his 19-point victory came despite the barrage of ads against him. About 450 club members and supporters cheered on Trump after dining on shrimp and cheese and sipping cocktails on a lawn as results poured from the five states.

“We have television screens all over and we are down at this gorgeous green at Doral and everything is working beautifully,” Trump said, recalling the Cadillac-sponsored golf tournament at his Miami-area course earlier this month. “And then a commercial comes on, the worst commercial. And I’m with these wonderful people from Cadillac, all these top executives, and I’m saying: ‘Look over there! Don’t watch it! Isn’t the grass beautiful? Look, look! Don’t watch.’

“And they came in waves—one after another after another—and it was brutal,” he said.

Pushing Rubio

The American Future Fund sent more than three-quarters of its nearly 4,000 ads to Rubio's home state. Before joining the “Never Trump” effort in recent weeks, it also targeted Kasich with TV ads that blasted him as a “cheerleader for Medicaid expansion” and hammered Cruz as weak on national security, according to the Center for Responsive Politics, a Washington-based group that tracks political spending.

Rubio was the only Republican candidate competing on Tuesday that the group hadn't criticized, the Center said.

Of the $7.5 million that Our Principles spent on television ads in states with primary contests on Tuesday, about $3.5 million was in Florida.

According to a Republican fundraiser with knowledge of the group, donors to Our Principles wanted to help Rubio in his home state, pressure that prevented the group from spending more in other states where polls showed Cruz was a better bet.

Packer Gage, who has said Rubio was her personal choice to be the party's nominee, noted that the group's data only recently showed the gap closing between Cruz and Trump in Illinois and Missouri. “Our data showed it closing too late for a week of television ads,” she said, adding that the group's polling came in on Friday after many TV affiliates were closed.

Public polls available earlier this month suggested all three states were much closer than the Florida contest. Cruz was down 10 points in Illinois, according to a Chicago Tribune poll on March 8; 7 points in Missouri, according to a Fort Hays State University survey; and 6 points in North Carolina in a Civitas poll on March 10.

Club for Growth Action shares pollster John Lerner with Conservative Solutions, the pro-Rubio super-PAC. It aired $2 million of television ads in Florida, or twice as much as they spent in either Illinois and Missouri, according to Doug Sachtleben, the group's communications director. The group purchased $7.5 million in anti-Trump ads during the nomination fight, he said.

“Florida was a place we felt there was a big need to be involved,” Sachtleben said. “For one, it's the biggest prize so far and represents so many delegates. And secondly, Trump has a unique relationship to Florida and we wanted to come into his backyard and lay out the case against him.

“Then the third reason would be Rubio,” he said. “We felt he would make a good nominee.”

Next Steps 

The race now moves into the final stretch, with the final 21 nominating contests scattered throughout the next 13 weeks. 

Kasich faces the biggest uphill climb: There are not enough delegates left for him to clinch the nomination, even if he won every one. He needs to keep Trump and Cruz below the 1,237-delegate threshold and hope he picks up enough momentum to win a contested convention. 

It's a tough fight for Cruz, too. His natural base is evangelical voters in the South, where primary voting is practically finished.

Packer Gage said her group will reassess, too, and may move away from TV advertising and focus on a delegate strategy. In that scenario, the group would focus on contacting delegates with anti-Trump messages in hopes of moving them away from the New York businessman on second or third ballot at the convention.

“We have the luxury of some time to determine where to go from here,” she said.

Conway, the Cruz adviser, said she is meeting with officials from the anti-Trump effort on Wednesday. She said the group's have failed to slow Trump because they aren't backing a specific alternative. Conway is also incensed the groups didn't help Cruz in Texas or Idaho on March 1, when he had a chance to win 50 percent of the vote and collect all the delegates.

“The ‘stop Trump’ folks may not care for Senator Cruz—he may not have been the second, third, fourth or fifth choice—but he's their only alternative if they really want to stop Trump,” she said.

Cruz, particularly when compared to Rubio, has never been a favorite of the party’s pro-business establishment. Many of those long-time lawmakers and party financiers, however, are turning to Cruz as the party's only option.

But Cruz will now have to defend himself against Kasich, who used his first victory in the nominating race to say he now has momentum that will carry him into the White House. 

Kasich also has fresh troops to help get him there, adding Stu Spencer, who served as Ronald Reagan's chief strategist; Charlie Black, a White House adviser for Reagan and both Bush presidents; former U.S. Representative Vin Weber of Minnesota; and Tom Ingram, a Tennessee-based strategist.

The announcement, which came in an otherwise pro forma news release, contained a strong signal of how serious Kasich is about fighting for the nomination by mentioning that Spencer was there the last time the nominee failed to win enough delegates before a convention.

“As chief political strategist to President Gerald Ford, Spencer played a central role in helping Ford secure the Republican nomination at the Kansas City Convention in 1976,” noted the announcement. 

With assistance from Sahil Kapur, Terrence Dopp, Kevin Cirilli, and Mark Niquette.