Peter Navarro’s new book won’t win him many new friends. For just one example of the former Trump trade adviser’s frequently, uh, pungent turns of phrase, he compares Jared Kushner to human excrement.

Nor does his disdain for the aspirant dauphin end there. Kushner, Navarro writes, is “nothing if more than a young and rich, run-of-the-mill liberal New York Democrat-cum–slum lord”.

In November, Navarro will go on trial for contempt of Congress. He refused to cooperate with the January 6 committee. If convicted, he faces up to two years in prison. On that note, his new book is both a not-so-subtle jab at the Department of Justice under Merrick Garland and a vehicle for crowdsourcing his criminal defense.

“Help finance legal effort AND put Trump back in” the White House, Navarro tweeted in June. “Order Taking Back Trump’s America today.” This month, he passed the plate again: “Buy the book today! We need our country back from these stooges and oppressors.”

Pro-Trump Trump books, however, are often full of inadvertent self-owns. Thanks to the work of other authors, we know Trump didn’t like aides who took notes, once berating Donald McGahn, his White House counsel, for such a misstep. And yet here comes Navarro, eager to tell the reader he kept lots of notes himself.

Page 240 contains a 25 June 2020 journal entry about a meeting of major donors who wanted “Kushner and Brad Parscale out the door” of the Trump campaign. Trump agreed but, Navarro writes, didn’t want to sack his son-in-law himself. One of the donors tried to do it – and failed.

Showing his notes, Navarro adds to a pile of evidence that Trump, the supposedly ruthless titan who fired people on TV, actually doesn’t dare fire people. Whoops. Just as well the boss doesn’t read.

On the one hand, Taking Back Trump’s America is a hurriedly written laundry list of Navarro’s many grievances. On the other hand, it is rollicking and filled with venom.

Navarro has substance, holding a Harvard PhD in economics and having taught at UC Irvine. But intellectual firepower should not be conflated with prudence or restraint. In the past, Navarro has liberally quoted a China expert who turned out not to exist, other than as an anagram of Navarro’s own name.

Between 1992 and 2001, Navarro mounted five campaigns for public office – each one unsuccessful. As a candidate, he derided Republicans for being wedded to “every man for himself” and argued that America “ought to progressively tax the rich to help everybody else”. Time passed. Positions shifted.

But Navarro is still a bomb-thrower. In his new book, Steve Mnuchin, Trump’s treasury secretary, Gary Cohn, Trump’s first economic adviser, and Mark Meadows, Trump’s last chief of staff, all get it in the neck.

Navarro recalls an argument in the Oval Office with Mnuchin over China policy. The words “Neville Chamberlain” and “Nazis” appear. Mnuchin is Jewish.

Navarro quotes himself: “Hey, Neville, knowing what you know about what the Nazis did to the Jews, how is it that you don’t give a flying puck” – bowdlerization the author’s own – “about what the Chinese communists are doing to two million Uyghurs in the concentration camps of Xinjiang Province … What do you say about that, Stevie?”

What does Navarro say about Trump’s adoration for Robert E Lee, Trump’s both-sides-ism over the neo-Nazi march in Charlottesville or even Trump reportedly having kept Hitler’s speeches on his nightstand? Nothing.

Navarro also advises us that his “favorite Roger Ailes quote” is “Truth is whatever people believe”. As Navarro’s book comes out, Fox News is being sued for billions, for hyping nonsense about voting machines and election interference. Elsewhere, even Trump’s lawyers are lawyering up.

Back to Kushner. Purportedly, Navarro came to Trumpworld via the boss’s son-in-law. If so, he demonstrates a marked gratitude deficit. He has even suggested Kushner faked a cancer diagnosis to help sell his own memoir, Breaking History.

“That thyroid thing, that came out of nowhere,” Navarro shared. “I saw the guy every day. There’s no sign that he was in any pain or danger or whatever. I think it’s just sympathy to try to sell his book now.”

Navarro’s renderings of Trump White House politics do make for engrossing reading. He writes that Kushner told him he wanted to “crush [Steve] Bannon like a bug” – and that Trump resented Bannon, his former campaign manager and White House strategist, for taking “too much credit for the 2016 win”.

And yet, when writing about that abortive coup against Kushner during the 2020 campaign, Navarro says the plotters wanted to replace Kushner with … yes, you guessed it, Bannon.

Navarro chooses not to examine the fact that had the coup succeeded, the campaign would have confronted a different set of problems. In August 2020, Bannon was arrested and charged with fraud. He denied it, took a pardon from Trump and now faces similar charges in New York state. He has pleaded not guilty again.

Legal jeopardy is in Trumpworld’s DNA. Ty Cobb, a White House lawyer during the Russia investigation, points out that it comes from the top down.

Speaking after the FBI searched Mar-a-Lago, seeking confidential documents, Cobb said: “I think the president is in serious legal water, not so much because of the search, but because of the obstructive activity he took in connection with the January 6 proceeding. That was the first time in American history that a president unconstitutionally attempted to remain in power illegally.”

Navarro can inveigh against Garland and the DoJ all he wants. His book does not alter a fundamental reality. His trial is set for 17 November – just in time for Thanksgiving.

• Taking Back Trump’s America: Why We Lost the White House and How We’ll Win It Back, is published in the US by Post Hill Press