Mr. Cruz has struggled to formulate a concise argument rebutting Mr. Trump’s claim that the top vote-getter deserves the nomination, alternately citing the number of former Republican presidential hopefuls now supporting him, general election polls and Mr. Trump’s “hard ceiling” of support.

On Wednesday, Mr. Cruz told reporters at the Republican National Committee’s spring meeting in Florida that only Mr. Trump’s loyalists believed that the candidate with the most votes should be awarded the nomination. When it was pointed out that a majority of Republican voters seemed to agree — 62 percent, according to an NBC News/Wall Street Journal poll last week — Mr. Cruz largely ignored that fact…

Anthony Scaramucci, a member of Mr. Romney’s New York finance team in 2012, said his party remained in denial about its voters’ preferences.

“There’s the spirit of something, and then there’s the letter of something,” he said. “I was a Scott Walker supporter. And then I was a Jeb Bush supporter. So I feel like I have some level of credibility. Donald Trump may not have been my first choice, but if he is in fact the people’s choice, I think my establishment friends are making a very big mistake by not acknowledging that.”