The Republican establishment has circled the wagons around Sen. Marco Rubio over the last two days as more than a dozen governors and members of Congress belatedly tossed their support behind him as their best hope for halting Donald Trump’s bid for the White House.
But they are also wondering if they’re too late, with one top Republican saying Mr. Trump’s easy victory over the weekend in South Carolina makes it more likely than not that he will be their nominee in November.
“I personally believe it’s down to a two-person race,” House Majority Leader Kevin McCarthy said on MSNBC’s “Morning Joe” — adding that Mr. Trump is ahead of Mr. Rubio in that contest. “The bigger advantage is to Trump. He’s got the momentum. I think there’s more [than] a 50 percent chance he’s the nominee.”
Mr. McCarthy has not picked sides in the race, but many of his colleagues rushed to do so, with Mr. Rubio adding the support of a sitting governor, four senators and nine House members on Sunday and Monday.
“Marco has a unique ability to effectively communicate detailed, conservative plans in a way that attracts people who do not normally vote for Republicans,” said Sen. Orrin G. Hatch, a Utah Republican who is also the president pro tempore.
Also lining up behind Mr. Rubio was former Minnesota Gov. Tim Pawlenty, a 2012 presidential candidate himself, who said Mr. Rubio is the unifier the GOP needs.
“I think he’s got the total package, and I think he’s going to bring forward the strongest voice, the strongest image and really the most thoughtful and informed, strong view about how to move this country forward from a conservative perspective,” Mr. Pawlenty said on CNN’s “New Day.”
The flood of support signals just how worried Republicans in Washington are about the prospect of Mr. Trump leading their party into November, after the billionaire businessman has notched two straight primary victories and is well positioned to win the majority of the states up for grabs in next week’s Super Tuesday contests.
“What’s happened here is that a lot of mainstream Republicans realize if they want to stop Trump, their best bet is Marco Rubio, even over Ted Cruz,” said GOP strategist Ford O’Connell. “As of today, Rubio gives the Republicans the best shot of winning in November.”
The endorsements come late in the process, but many lawmakers felt trapped by the large number of establishment-style candidates who were in the field at the beginning of the race. Former Florida Gov. Jeb Bush’s decision this weekend to end his campaign freed many of those Republicans to make a choice.
They picked Mr. Rubio over Ohio Gov. John Kasich, the other candidate seeking support of the establishment wing of the party.
The flood of support to Mr. Rubio stands in stark contrast to Mr. Trump, who still has no endorsements from a sitting governor or member of Congress. So far that hasn’t hurt him.
Indeed, last week Mr. Rubio campaigned across South Carolina with Gov. Nikki Haley, Sen. Tim Scott and Rep. Trey Gowdy — a quartet Ms. Haley described as a sort of Benetton diversity ad, since she is Indian-American, Mr. Scott is black, Mr. Gowdy is white and Mr. Rubio is Hispanic.
Mr. Trump, meanwhile, usually took the stage alone at his events — though he did have the backing of South Carolina Lt. Gov. Henry McMaster.
At his victory party Saturday, Mr. Trump bragged about it.
“I will take him over the governor anytime, because we won,” he said.
David Damore, a political science professor at the University of Nevada, Las Vegas, said it seems that a lot of elected officials who had supported Mr. Bush are now moving toward Mr. Rubio, hoping to give him a last-minute boost.
“But if it is simply a name with no organization behind it, not sure what the value is and certainly opens him to criticisms by Trump and Cruz that Rubio is the second or third choice of the establishment wing,” Mr. Damore said in an email.
Trying to combat that perception, Mr. Rubio on the campaign trail last week argued he’s still an insurgent within the GOP. Campaigning with Ms. Haley and Sen. Mike Lee, Mr. Rubio said all three of them had to defy establishment-backed candidates to win their current seats.
The same is true of Mr. Cruz, who toppled the establishment-backed sitting lieutenant governor in 2012 to win the GOP’s nomination for senator from Texas.
Mr. Trump, however, said the fact that none of Mr. Cruz’s fellow senators will back him shows the Texan rubs people the wrong way.
Mr. O’Connell, the GOP strategist, said Mr. Trump is trying to squash Mr. Cruz’s campaign quickly.
“Trump wants to crush Cruz before Rubio lines up everyone else,” Mr. O’Connell said. “If Cruz bows out before Rubio can consolidate, that means that Trump’s going to be hitting 50 percent in the polls.”
As the campaign expands across the nation next week, Mr. Cruz has a solid base of support and organization in the March 1 contests, including in his home state of Texas.
“Part of our strategy is to do well on March 1, because that’s the biggest single day for delegates,” Cruz spokesman Rick Tyler said on Fox News Monday. “We’ve got the organization. We’ve got a candidate with a message. He is now the only conservative left in the race with a path to victory. So we feel very good about March 1.”
Mr. Cruz has also demonstrated an ability to raise prodigious sums of money since entering the race last March. He raised $7.6 million in January and finished the month with $13.7 million on hand. Both figures were more than any other GOP candidate in the field. Mr. Cruz also spent the most, though, at $12.7 million.
Mr. Rubio, meanwhile, raised $4.9 million in January, but he also spent $10.3 million and finished the month with a little more than $5 million on hand, second to Mr. Cruz.