But longtime observers of Utah politics say that Mr. Romney’s failure to secure the nomination happened not because he has rebuffed the president, but because the convention’s hard-right delegates were angry that Mr. Romney had tried to circumvent them with a second route to the nomination: signature gathering.

“It would be a mistake to say that what happened in the convention was about Donald Trump,” said Jason Perry, director of the Hinckley Institute of Politics at the University of Utah. “This was about other factors,” he went on. “Delegates do not like power being taken away from them.”