According to a new book, President Joe Biden doesn’t trust some members of his Secret Service detail, believing them to be supporters of his predecessor, Donald Trump, The Hill reports.

Chris Whipple makes the claim in The Fight of His Life: Inside Joe Biden’s White House, which Scribner plans to publish on Jan. 17. A Kirkus critic praised the book, writing, “There’s more to the current administration than meets the eye, and Whipple is a reliable, readable interpreter.”

Whipple details “Biden’s discomfort with his Secret Service detail; some of them were MAGA sympathizers.” Whipple writes, “He didn’t trust them.…Surrounded by a new phalanx of strangers, Biden couldn’t help but wonder, Do these people really want me here?”

Biden also doubted a report that his dog Major had bitten a Secret Service agent. Whipple writes, “Somebody was lying, Biden thought, about the way the incident had gone down.”

It was previously reported that Whipple’s book details a strained relationship between Biden and Vice President Kamala Harris, whom he allegedly called “a work in progress.” And the Kirkus reviewer writes that Biden referred to Trump as “a fucking asshole.”

Scribner says that Whipple’s book, his third, “delivers a stunning portrait of politics on the edge.”

Michael Schaub, a journalist and regular contributor to NPR, lives near Austin, Texas.