Over many decades, people who have entered Mr. Trump’s circle have discovered that they are bit actors in a movie he sees himself starring in.

“People are not people to him, they are instruments of his ego. And when they serve his ego, they survive, and when they don’t, they pass into the night,” said Tony Schwartz, the ghostwriter on “The Art of the Deal,” Mr. Trump’s first book. “Ultimately, the fate of anyone who casts their lot with Trump is — you are passing through. And I just can’t think of anybody for whom it is not true.”

Jack O’Donnell, the former president of Trump Plaza Hotel and Casino in Atlantic City, and a vocal critic of his former boss, said many people have cycled through his world remarkably quickly without leaving much of an impression on Mr. Trump.

“This is an individual who completely lacks compassion and empathy, and therefore the recycling of people, people crashing and burning, it means nothing to him,” Mr. O’Donnell said. “He might put on a public frown for a day because he’s upset that, in his mind, the admiral got railroaded out. But Trump couldn’t care less about the admiral.”