The president browbeat the former homeland security secretary for refusing to break the law, according to A Very Stable Genius

Donald Trump “abused”, “harassed” and “pestered” his homeland security secretary over immigration policy, demanding that the US border be closed, a new book reveals.

And when the then secretary, Kirstjen Nielsen, warned the president that shutting down the border would be illegal, the then attorney general, Jeff Sessions, approved the radical measure – despite it being against the law.

Spare us the self-serving excuses, Kirstjen Nielsen. You were the worst | Richard Wolffe Read more

Trump’s obsession with curbing border crossings and building a wall is laid bare in A Very Stable Genius, written by the Washington Post journalists Philip Rucker and Carol Leonnig, which is being published by Penguin and a copy of which was obtained by the Guardian.

Nielsen was sworn in as the sixth homeland security secretary in December 2017, succeeding John Kelly, who became White House chief of staff. It was a thankless task under a president with obsessive tunnel vision on illegal immigration. Trump habitually complained to aides that Nielsen was not doing enough to tackle the problem, the book recounts.

“In some instances, the volatile president was verbally and emotionally abusive toward Nielsen,” the authors write. “‘Kirstjen, you’re just not tough enough,’ Trump would tell her. Trump complained Nielsen did not “look the part” of homeland security secretary.

“He made fun of her and believed that at about five feet four inches she was not physically intimidating. ‘She’s so short,’ Trump would tell others about Nielsen. She and Kelly would try to make light of it. Kelly would rib her and say, ‘But you’ve got those little fists of fury!’”

A Very Stable Genius describes a cabinet meeting in May 2018 where Trump assailed Nielsen in front of about two dozen administration officials over an increase in illegal border crossings. The president was “red faced” and launched an “explosive, extended tirade”, according to the book.

Sessions, who had fallen out of favor, saw a chance to get back in Trump’s good books, it continues. The attorney general said: “I just think we’re not being tough enough. I think we need to shut down the border.”

Rucker and Leonnig write: “Trump concurred and, turning to Nielsen at the far end of the table, asked, ‘Why haven’t you shut down the border?’ It was more of an admonition than a question. Nielsen knew this would be illegal, not to mention economically disastrous because it could choke off trade routes.

“‘I’m not sure what we are saying here,” Nielsen said. ‘As the attorney general knows, people have a legal right to cross the border and try to claim asylum. That’s just the law.’ Trump looked back at Sessions. ‘No,’ Sessions said, ‘we should just shut the border down.’”

The president furiously berated Nielsen, the authors go on. “Trump was so worked up that some attendees thought he looked manic. Kelly silently shook his head at Nielsen to signal to her to stop engaging with the president. [Jared] Kushner made eye contact with Nielsen and moved his finger across his neck to signal to her to cut it off.”

No one in the room stuck up for the homeland security secretary. But after the cabinet meeting had finished, Mick Mulvaney, then White House budget director, told the president: “You know, the attorney general was wrong about the law. The attorney general is saying this, but that is not the case.”

Facebook Twitter Pinterest Kirstjen Nielsen defends the policy of family separations at the border in June 2018. Photograph: Michael Reynolds/EPA

For the rest of the year, according to the book, Trump’s bullying behavior towards Nielsen continued. He “harassed” her with angry phone calls, sometimes waking her at 5am, and “pestered” her late at night. He often called her after watching the Fox Business host Lou Dobbs complain about illegal immigration and offer wildly unrealistic policy prescriptions.

“The president would routinely call Nielsen to say a version of ‘Did you see Lou Dobbs? You’re totally fucking embarrassing me. This is my issue!’… Sometimes, Trump would refer to one of Dobbs’s proposals and say, ‘Kirstjen, just do it. Just do it.’ ‘But we can’t do it,’ Nielsen would explain, usually because whatever Dobbs had uttered on TV was against the law.”

After one flashpoint, Nielsen called Dobbs and politely offered to help his reporting. Hours later, Trump phoned Nielsen. “Did you call Lou Dobbs?” he asked. She said yes. Trump replied: “That’s great. Lou says you’re very smart!”

Within a year, Nielsen, Kelly and Sessions would all be gone. Mulvaney succeeded Kelly as acting chief of staff. The number of people crossing the border fell for the seventh consecutive month in December, but Trump continues to pursue funding for a wall.

In often alarming detail, A Very Stable Genius chronicles the wild ride of the Trump presidency, including special counsel Robert Mueller’s investigation into Russian election interference. It reports that Rod Rosenstein, then deputy attorney general, and the FBI director, Chris Wray, were appalled by Republicans in the House of Representatives secretly promising Trump they had evidence of a cover-up in the investigation.

The normally mild-mannered Rosenstein erupted when he learned of a death threat against his wife, Lisa, deemed credible enough for the family to be given a 24/7 security detail. Devin Nunes of the House intelligence committee had been accusing Rosenstein’s justice department of concealing evidence.

“You’ve got to stop this,” Rosenstein told Nunes, according to the book. “This is ridiculous. You’re ginning up all these ludicrous conspiracy theories. You’re accusing me of being part of some vast leftwing conspiracy. I’m a lifelong Republican. My wife is a Republican. She’s getting death threats from these nuts.”

Rosenstein resigned last April after nearly three decades at the justice department.