Hunter Biden was a nasty husband. On top of his penchant for addiction and excess, verbal abuse littered his marriage to Kathleen Buhle. In her memoir, If We Break, Buhle recounts how the 46th president’s surviving son regularly taunted her for supposed intellectual shortcomings.

Amid booze-soaked benders and drug-fueled rages, Biden called his wife “goddam dumb”, the “dumbest person” he had met. “Get away from me, you idiot,” he purportedly thundered.

Buhle discovered text messages that showed she wasn’t alone in suffering such tirades.

“He was mean at times, and strangely tender, with dozens of women,” Buhle writes. “I was struck by the number of them who clearly thought they could save him.”

Buhle attended a Catholic high school then graduated from St Mary’s University in San Antonio with a degree in psychology. Biden pocketed degrees from Georgetown University and Harvard Law School, but declined to look too deeply into the mirror. Socio-economic disadvantage is not to blame for his penchant for crack, prostitutes and self-pity. Buhle writes that she once told him: “Hunt … a kid from a middle-class family does not have a ballroom.” He also had a “tuxedo hanging in his closet – a tuxedo he used fairly regularly”.

The conservative muckraker Peter Schweizer has shredded the Bidens for their business dealings. Yearning for catharsis as much as for score-settling, Buhle says she knows nothing of her former husband’s financial escapades.

“I liked the nice things,” she admits. “I didn’t want to think about the cost at which they were coming.

Otherwise, she has plenty to share. Subtitled “A Memoir of Marriage, Addiction and Healing”, her book is a dagger.

The couple met in 1992, as members of the Jesuit Volunteer Corps. They married the next year and had three daughters. For Hunter, alcoholism and tax problems surfaced in the early 2000s. Later, the US navy expelled him for using cocaine. In 2017, he and Buhle divorced.

If We Break is easy reading, published in time for Father’s Day. It leaves you wondering how and why Joe Biden pursued the presidency in 2020 when all this family drama was percolating away. Hunter’s laptop, a computer he once owned that Republicans claim is full of incriminating material, debuted before election day. It is still producing stories. If We Break may shock but it does not surprise.

Buhle demonstrates better judgment than her ex-husband, who published his own memoir last year. She knew when to walk away. He had difficulty letting go. More important, she understood that not that all broken things can be repaired.

Buhle possesses an awareness of self and circumstances her ex-husband evidently lacks. For example, in 2015, just minutes after Beau Biden, his brother, was buried, Hunter contemplated running for elected office as Beau once did, becoming attorney general of Delaware. Buhle’s reaction was short and to the point.

“What are you talking about? You’ve only been sober a few days … This is insane. Please don’t mention anything to the girls.”

Hunter did blab – in Beautiful Things, his self-reverential confessional.

“I underestimated how much the wreckage of my past and all that I put my family through still weighed on Kathleen,” he wrote.

Think self-absolution and exhibitionism, rather than contrition, in an episode that preceded a fling with his late brother’s wife.

“He said it was his duty to take care of Hallie and her kids,” Buhle writes. When she learned of their affair, all she could muster was: “Oh my God.” She says she didn’t cry. At that moment, she writes, she “knew in some way that he couldn’t hurt [her] any more”.

For what it’s worth, the Old Testament obligates the brother of a childless man to marry the widow. But Beau had two kids and anyway, religious duty was most likely not on Hunter’s mind. In 2018, according to emails harvested from that laptop, Hunter insisted Hallie test for HIV.

Joe Biden makes only rare appearances in If We Break. Buhle depicts him as a loving father and kind father-in-law. He greeted her when they first met by putting “his hands on [her] cheeks and look[ing] me in the eyes, his nose almost touching my own”. Then a senator, Biden told her: “Honey, my boy tells me he loves you, so that means I love you too. Understand? I love you.”

At the time, she was pregnant. Buhle also writes that Biden introduced her “as his daughter everywhere we went” and that the family saw the future president as “the sun around which we all revolved”.

A lot revolves around Hunter. A federal criminal investigation proceeds. Taxes are only part of his worries.

For his father, in terms of political pressures, inflation is on the rampage, approval numbers circle the drain. Democratic cognoscenti harbor serious doubts about the president’s capacity to govern. David Axelrod, Barack Obama’s senior strategist, casts Biden’s age as a major liability. Alexandria Ocasio-Cortez declines to say if she will back a reelection bid.

Yet Biden was the only Democrat capable of unseating Trump. The bench is neither wide nor deep.

Count Katherine Buhle’s memoir as another addition to the canon of opposition research on the Bidens, should Joe Biden run for re-election. Buhle shouldn’t expect a thank you note from Kevin McCarthy or Mitch McConnell, but she has earned one.

• If We Break: A Memoir of Marriage Addiction and Healing is published in the US by Crown Publishing