Still, there’s no question she has useful knowledge of our ruling clique. Perhaps the most interesting thing about “Unhinged” is its insights into how Manigault Newman, a former Democrat who’d worked in Bill Clinton’s White House, rationalized being part of Trump’s white nationalist campaign. I’ve always been mystified by how the president’s enablers, who understand his venality and incompetence, justify their behavior to themselves. (Even most bad people want to believe that they’re good.) Manigault Newman is an unreliable narrator, but her book is still the best account we have of how the Trump cult — a term she uses repeatedly — looks from the inside.

Her version of her own motivations is probably sugarcoated, but it still isn’t pretty. She’d been part of a pro-Hillary Clinton “super PAC” and was bitter that she didn’t get a job on Clinton’s campaign. Meanwhile, Manigault Newman, who grew up in poverty, knew she owed her cherished celebrity to Trump. (As she points out, he likes to surround himself with fame-worshiping people whose fortunes depend on him.) “The Trump team, unlike HRC, was true to its word and had officially brought me on board as a senior adviser and director,” she writes. “Regardless of whether Mr. Trump was being taken seriously, I was.”

She suppressed whatever unease she felt about selling out by trying to convince herself that she was representing African-American interests in the campaign and administration. Manigault Newman did graduate work at Howard, the revered historically black university. She had roots in African-American Democratic politics. When she switched sides to back Trump, the disgust of old friends and colleagues hurt. Throughout “Unhinged,” you sense her trying to explain herself to them.

Studies have shown that the people who are most likely to leave cults are those who maintain intimate links to people outside them. Manigault Newman, who last year married a pastor who campaigned for Hillary Clinton, could never fully sever ties with Trump critics.

In the end, you don’t have to trust her sincerity to see “Unhinged” as a serious indictment of Trump. Either she is telling the truth when she calls Trump “a racist, a bigot, and a misogynist” in serious mental decline, or the Trump campaign’s former director of African-American outreach, a woman frequently called upon to testify to Trump’s lack of racism, is a lying con artist. No matter how little credibility Manigault Newman has, the man who gave her a top-ranking job in his administration has less.