Confidence Man: The Making of Donald Trump and the Breaking of America by Maggie Haberman:
When all the results were in, Trump ended up with 24 percent of the vote, just over three points behind Texas senator Ted Cruz and edging out Florida senator Marco Rubio for second place. When Trump took the stage that night at an election-night party in West Des Moines, he was somewhat subdued, but startlingly gracious. “We finished second, and I want to tell you something, I am just honored,” Trump said before leaving for New Hampshire. He declined to speak to his Iowa-based staff, viewing them as failing him.
Within hours, it was clear that Trump had accepted nothing about the result. His equanimity about defeat had dissolved into fury. “It was stolen from me,” Trump told his advisers. For days thereafter, he called Iowa’s Republican chairman daily with an order to redo the vote, threatening to sue over what he called “fraud.” Trump fixated on a few perceived infractions by the winner, including a supposed dirty trick in which Cruz’s campaign disseminated a rumor at caucus locations that Carson was leaving the race. “One of the most disgusting things I’ve ever seen,” Trump told a radio host. He ultimately spent much of the week before the New Hampshire primary complaining to the state’s voters that “Ted Cruz didn’t win Iowa, he stole it.”