The Newsom of caricature is a lucky, wealthy It boy who spent his summers with the billionaire Getty family. In the book he says that his life isn’t what it seems, and lifts the lid on deep unhappiness at home as well as explaining his various regrets. It’s part confession, part demon-facing, part pre-campaign hygiene before a possible White House run.

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The “young man in a hurry” of his title could also describe his father, Bill Newsom, a failed politician who became a judge and went on to administer the Getty family trust. His mother, Tessa Menzies, was more than ten years younger than Bill and their marriage was short-lived. Gavin felt like a constant disappointment to his father, who loved literature and was ready to share the “Russian greats, the English greats, and, most proudly, the Irish greats” but had a son who did not, could not follow suit. “Who would have guessed — certainly not my father — that his only son would be dyslexic,” he writes. His teachers didn’t guess either, leaving him struggling with the condition undiagnosed.

His mother offered the opposite problem: low expectations. “It’s OK to be average, Gavin,” she once told him. “I understood even back then that this, too, came from her deep reservoir of love for me. But I don’t recall crueller words ever said about me,” he recalls.

But there was another life. His father was a lifelong friend and confidant of Gordon Getty, the son of the oil magnate J Paul Getty. They were close enough that young Gavin grew up moving between his mother’s three-job lifestyle (she balanced being a bookkeeper, secretary and waitress) and the world of one of the richest families in America. At times the juxtaposition is jarring — his father comes across as careless at best, enjoying luxury with friends, while Newsom’s hard-up mother sits at home and pours herself a drink from “her Safeway jug of wine”.

In the book he tells the story of his father driving him to a toy shop but making a detour to pick up Eugene Paul Getty III, one of J Paul’s grandsons. The young man, known as Paul, was missing an ear because it was severed when he was taken hostage as a teenager. Newsom’s father (who had helped to deliver the ransom money) had urged his children not to ask about the ear. After a few minutes in the car, Newsom’s sister spoke up: “Paul, how many ears do you have?” The reply: “I’ve got one ear on the side of my head and the other one stuck in my brain.” Eight years after the kidnapping, a drug overdose left him quadriplegic.

Through the Gettys, Newsom was taken on starry adventures across Europe. He left his cash-strapped home for suit fittings on holidays where the tailor said he needed “clothes appropriate to be a king”. When expensive gifts arrived via the Gettys, his mother feigned enthusiasm. But they both knew what to do: take the designer gift back to the store for a cash refund so she could buy new, cheaper gifts.

The Gettys would later lend the family mansion for Newsom’s wedding reception and chip in when he launched his first business, PlumpJack Wines, in 1991, aged 24. The same network that bought the bottles would later write the campaign cheques.

But his book makes a point of the negatives of his being adopted into San Franciscan royalty. “The Getty connection would cloud and distort many things,” he writes. “In the eyes of the press, I was for ever the ‘golden boy’ whose daddy had prospered because of his ties to the Gettys and now the son was simply following suit.” When he went into politics, he had to fight off accusations that he was “the pampered one”.

There are plenty of other regrets — such as his marriage in 2001 to Kimberly Guilfoyle, who ended up engaged briefly to Donald Trump Jr and is now the US ambassador in Greece. Even before the wedding he was unconvinced, he writes. It didn’t improve much after the vows: “I was better when I was alone. She’d fly back and we’d go into pretend mode for a week or two, the mayor and the first lady.” The “pretend mode” was powerfully evident when they posed for a Harper’s Bazaar shoot lying down on an oriental carpet. It was supposed to be “a gag shot”, he writes, yet ended up as part of a glossy spread. “The critics mocked it, but none more than me.” They separated after four years of marriage.

Newsom launched a wine business in 1991, aged 24

STEVE CASTILLO/SAN FRANCISCO CHRONICLE VIA GETTY IMAGES

He then had an affair with the wife of his deputy chief of staff, which he presents as a calamitous decision. “You’re not some single guy,” he quotes his therapist as saying. “You’re the goddamn mayor. You’re 39 years old. And what are you doing getting involved with a staff member?” The penny dropped. “It would become clear to me that what I had done was not just a transgression that tore at friendships and staff,” he writes. “It was the worst betrayal of my life.” Since 2008, he’s been married to the documentary-maker Jennifer Siebel.

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What of the politics? Like any good CV, Newsom is quick to offer stories that show his principles, as he would on a CV. He describes how he pushed for gay marriage in 2004 and watched establishment Democrats turn their backs on him — including Obama. “When we found ourselves at the same fundraiser hosted by [the former mayor of San Francisco] Willie Brown, Obama told Willie he wanted no picture taken of the two of us. The snub bothered Willie enough that he later shared the story with the press.” Obama, he notes with some satisfaction, would eventually come round, doing for the nation what Newsom had done for San Francisco.

The Trump chapters present an adversarial relationship that is also oddly human. When Newsom gave a speech about “the corruption and incompetence in the White House,” Trump called him personally, wounded. “Gavin, hey: I thought you and I had something.” At the Paradise wildfire in 2018 (the deadliest in Californian history with 85 casualties) they toured the wreckage together and Trump later showed Newsom around Air Force One. The public war was real: under Newsom, California filed 122 lawsuits against the Trump administration. But the private relationship was more complicated than either man’s public posturing suggests.

Yet Newsom is still keen for some point scoring. He recalls Trump telling him a story about how he tried to set up his daughter Ivanka with the NFL quarterback Tom Brady only to discover she was already dating “some schmuck”. That schmuck turned out to be Jared Kushner, who was sitting there as his father-in-law lamented what could have been.

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On homelessness — California’s most visible failure and his most dangerous liability — Newsom has far less to say. He blames Ronald Reagan for being “responsible for the rise of homelessness in America” and sidesteps what happened on his own watch (when the crisis deepened). For many Americans, California has become synonymous with high crime, high homelessness and a cost of living crisis. But Newsom sees it as a template, focusing on climate as an antidote to Trump and presenting himself as a liberal going against dark forces that cannot be named.

The childhood wounds, the Getty patronage, the glossy missteps and the betrayals are arranged to explain the man and disinfect the record. It’s an efficient act of political inoculation. Before a Republican opposition researcher assembles the file, Newsom has already written the first draft of the defence. We see him as self-aware, battle-tested and versed in confrontation with Trump. But is it convincing? At times the prose is flowery, but his life has been interesting (and wild enough) to make for a colourful read. That may not be enough to convince middle America that a Californian politician is the answer to their problems. But the book sends a clear overall message: yes, he is running.

Young Man in a Hurry: A Memoir of Discovery by Gavin Newsom (Bodley Head £25 pp304). To order a copy go to timesbookshop.co.uk. Free UK standard P&P on orders over £25. Special discount available for Times+ members