As he lost the public support of those once willing to step forward on his behalf, Mr. Trump grew angry over his news coverage and told people close to him that he would be fine without Mr. Mattis. He rebuffed them for even expressing concern.
Mr. Trump also privately groused about having to postpone departure plans for his 16-day trip to Mar-a-Lago, his Florida resort. On Friday, Melania Trump, the first lady, had already made plans to leave town with the couple’s son Barron, according to her spokeswoman. Mr. Kushner and his wife, Ivanka Trump, the president’s daughter, who are also planning to go to Mar-a-Lago, were preparing to stay with Mr. Trump in Washington, an administration official said.
Outside the family, a litany of staffing problems loomed as the shutdown deadline drew nearer. Mr. Trump privately complained that Mr. Mulvaney, who stepped into the vacancy left by John F. Kelly after others turned down the chief of staff position, had given him few options for averting the shutdown.
As the day drew on, reports surfaced that Mr. Mulvaney, who is set to take over for Mr. Kelly on Jan. 2, had once called Mr. Trump’s plans for a border wall “absurd and almost childish.”
The consequences of Mr. Trump’s self-sown chaos reverberated throughout the broader Trump orbit, where some conservatives alarmed by Mr. Mattis’s departure said privately that they were finally fed up with the president and regretted having worked to support him. Other allies agreed with his idea for a path out of the Middle East, just not the chaos with which it was done.
With whispers abounding through Mr. Trump’s camp, Democrats were far more willing to point out publicly what people close to the president said privately.
“The institutions of our government lack steady and experienced leadership,” said Senator Chuck Schumer of New York, the minority leader. “With all of these departures, it’s about to get even more unsteady. The president is making decisions without counsel.”