President Trump’s spat with Omarosa Manigault Newman, the White House adviser who was fired in December for “serious integrity issues,” is another of those particularly Trumpian innovations in public life — the raging dumpster fire that continues to yield new trash.

In her juicy new tell-all, aptly titled “Unhinged,” Ms. Manigault Newman paints an unflattering portrait of the president, whom she has known since appearing as a contestant on his reality TV show “The Apprentice” in 2004. She characterizes Mr. Trump as a racist, misogynistic narcissist with poor impulse control, severe attention-deficit issues and signs of creeping mental decline, who “loves the hate,” “thrives on criticism and insults” and “delights in chaos and confusion.” Her anecdotes range from the prosaically awful (she claims he has used the N- word ) to the freakish (she says she once walked into the Oval Office and found him eating paper). She says the Trump campaign offered her a $15,000-a-month sinecure to keep quiet about her on-the-job experiences. (A copy of the agreement has become public.) And, oh yes, she has secret audio recordings to corroborate some of her claims, including a recording of her firing by the White House chief of staff, John Kelly, in the Situation Room.

Mr. Trump has responded with characteristic restraint. He has dismissed Ms. Manigault Newman as “wacky”; called her a “lowlife”; mocked her for her having, he claims, weepily begged him for a job in the White House; and said she was “hated” by her colleagues for being “nasty,” “vicious, but not smart” and “nothing but problems.” Despite all this, insists Mr. Trump, he had tried his best to make things work because Ms. Manigault Newman always said “GREAT things” about him. For this president, there remains no higher job qualification than constantly telling him and others what a super guy he is.

On both sides, the spat is vintage Trump: tawdry, cruel, vindictive and highly personal. That said, this is about more than a petty feud with a former aide who famously shares Mr. Trump’s love of chaos, confusion and high drama. It is also a glaring reminder of one of this president’s central failings as a leader: his disastrous judgment when choosing people with whom to surround himself.