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.
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.
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.”
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.”