Among those in the room were Kirstjen Nielsen, the homeland security secretary at the time; Mike Pompeo, the secretary of state; Kevin K. McAleenan, the Customs and Border Protection chief at the time; and Stephen Miller, the White House aide who, more than anyone, had orchestrated Mr. Trump’s immigration agenda. Mick Mulvaney, the acting chief of staff was also there, along with Jared Kushner, the president’s son-in-law, and other senior staff.
Ms. Nielsen, a former aide to George W. Bush brought into the department by John F. Kelly, the president’s former chief of staff, was in a perilous position. She had always been viewed with suspicion by the president, who told aides she was “a Bushie,” and part of the “deep state” who once contributed to a group that supported Jeb Bush’s presidential campaign.
Mr. Trump had routinely berated Ms. Nielsen as ineffective and, worse — at least in his mind — not tough-looking enough. “Lou Dobbs hates you, Ann Coulter hates you, you’re making me look bad,” Mr. Trump would tell her, referring to the Fox Business Network host and the conservative commentator.
The happiest he had been with Ms. Nielsen was a few months earlier, when American border agents had fired tear gas into Mexico to try to stop migrants from crossing into the United States. Human rights organizations condemned the move, but Mr. Trump loved it. More often, though, she drew the president’s scorn.
That March day, he was furious at Mr. Pompeo, too, for having cut a deal with Mexico to allow the United States to reject some asylum seekers — a plan Mr. Trump said was clearly failing.
A complete shutdown of the border, Mr. Trump said, was the only way.
Ms. Nielsen had tried reasoning with the president on many occasions. When she stood up to him during a cabinet meeting the previous spring, he excoriated her and she almost resigned.