Every day, Hunter Biden calls his sponsor three times, trying to keep his drug and alcohol addiction at bay. Every night, by his own account, President Biden calls him before he goes to bed — and, if Hunter doesn’t pick up, a string of texts follows. And almost every minute, he says, he realizes how tenuous his life still is.

“I’m concerned. I really am. In the sense of, I have a healthy fear,” the president’s only living son said at the end of a 90-minute discussion with Marc Maron on his “WTF” podcast. “I’m not living in that. But you know, I’m leaving here and I’m going straight home.”

Over the past two weeks, after two years of being a largely silent character in an explosive narrative at the center of a presidential campaign, Hunter Biden is increasingly emerging, with a new book and interviews. The story he tells is in a sense familiar to the Biden family — trauma, tragedy and a deep well of grief, followed by redemption and a return from improbable odds.

But Hunter’s story fits uneasily into the Biden mold; so many of his problems were self-inflicted, as he moved through a haze of drugs and alcohol. He fathered a child and denied it until a paternity test proved otherwise. He jumped into business dealings that benefited from his father’s name. He is currently embroiled in a tax investigation, though he maintains his innocence.

On Dec. 9, 2020, President-elect Joe Biden's son Hunter Biden said the U.S. attorney's office in Delaware was investigating his tax affairs. (Reuters)

What becomes vividly clear is the sheer depth of the alcoholism and drug addiction Hunter is fighting and the ever-present danger of a relapse that could endanger not only his own health and life, but his father’s well-being and even the trajectory of his presidency.

“I have a healthy fear of relapse,” Hunter, 51, told NPR recently. “It’s too much a part of my story. I’m only one choice away from being back exactly where I was. And that’s the conundrum for everyone that’s in recovery. It never goes away. It only hides.”

By his own account, he remains in a fragile state that requires frequent attention from his father.

Hunter repeatedly says that his new book, and a brief media tour linked to it, is something of a therapy session for him, a way to talk about his struggles with addiction and exorcise past demons. It also allows him to try to shape public perception and recast a narrative that could be brutally challenged in coming months, a prospect that shadows his father’s presidency.

Republicans continue to target him, and will gain subpoena power if they win the House or Senate next year. The federal tax investigation could wrap up in coming months. A laptop purportedly belonging to him is still being mined — the Daily Mail recently published sexually explicit photos, as well as texts between Hunter and his father, and Hunter and his therapist.

Hunter declined interview requests for this story, and several close friends and family members did not respond to requests for comment. His publicist said he was only speaking to broadcast outlets, and for now avoiding print media.

The history of troubled presidential children is extraordinarily long, and it’s far more apparent among sons than daughters.

Andrew Johnson’s oldest son died after being thrown off a horse, his middle son was an alcoholic who died by suicide, and his youngest suffered from tuberculosis, drank to excess and died at age 26. Andrew Jackson’s son died in a hunting accident. John Tyler and John Quincy Adams each had sons who were alcoholics and died young.

Franklin D. Roosevelt had five adult children with 19 marriages between them, with one son becoming the center of a national scandal for using his father to obtain lucrative contracts.

“That story is just repeated over and over and over again. It’s truly shocking,” said Doug Wead, author of the book “All the Presidents’ Children.” “Alcoholics, early deaths. Accidental deaths. It’s a phenomenon. We could go on for hours.”

Often, the troubles are tied to a struggle to meet expectations set by their ambitious, absentee fathers. “The presidency is marble. It endures,” Wead said. “All of the children in these stories, they are the ones who fall.”

In this case, Hunter has an ongoing connection to a sitting president who has already lost two children, and whose daily struggles with foreign and domestic crises are compounded by the need to keep his surviving son from again going over the edge.

Biden has one other living child — his daughter Ashley, 39, an activist and social worker who runs an apparel company that donates proceeds to charity. His older son, Beau, a former attorney general of Delaware, died of cancer in 2015. And his infant daughter Naomi died in a 1972 car crash that also killed Biden’s first wife.

In Hunter’s account, no blame for his struggles attaches to his father. Joe Biden is the figure usually attempting — and, like many family members of addicts, frequently failing — to help his son through a life overwhelmed by alcohol and drugs.

It’s only now becoming clear how much the early stages of Biden’s campaign were shadowed by Hunter’s struggles.

In the weeks before his father announced his run, Hunter’s book recounts a major confrontation between father and son. Hunter, in the midst of his latest bender, comes to dinner, only to find family members waiting to stage an intervention; he storms out, furious, his father chasing after him.

“He grabbed me in a hug — and grabbed me, a big bear hug,” Hunter recalled on CBS News. “And he said — he just cried, said, ‘I don’t know what to do, I don’t know what to do.’ I thought, ‘I need to figure out a way to tell him that I’m going to do something, so I can go take another hit.’ It’s the only thing I could think.”

Promising to undergo another round of rehab, Hunter flew to Los Angeles intending to disappear. When his father announced his presidential run, Hunter was the only close family member not there.

The stories now emerging of Hunter’s addiction are harrowing. While Joe Biden is a teetotaler, Hunter’s first sip of alcohol came as an 8-year-old, when he drank champagne underneath a table at one of his father’s Senate reelection parties.

Years later, he found himself hunting desperately for crack cocaine in Franklin Square around the time his father, two miles away on Capitol Hill, was spearheading a crime bill cracking down on drug abuse.

Beau helped get Hunter treatment in 2003, and he stayed sober for a time. But the worst of it came after Beau died in 2015. At one point, Hunter entered a romantic relationship with his brother’s widow, something he now acknowledges was problematic, saying it was a romance built on grief.

He took to drinking a quart of vodka a day at home alone, at times unable to resist a swig on the short walk back from the liquor store. His cravings nearly interfered with a meeting with the king of Jordan in Amman to discuss Syrian refugees.

“I’d wake up and have to reach under the bed for the pint of Smirnoff I hid just to get into the shower,” he said on the “WTF” podcast. “That’s when I reached bottom.”

But it wasn’t. He started taking cocaine on a 2016 trip with his daughter to Monte Carlo to meet with officials of Burisma, a Ukrainian gas company on whose board he served.

“I spent more time on my hands and knees picking through rugs, smoking anything that even remotely resembled crack cocaine,” he said on “CBS Sunday Morning.” “I probably smoked more Parmesan cheese than anyone that you know, I’m sure.”

Finally, his father — then vice president, a national leader and regular presence in the gilded halls of power — confronted him in his dingy apartment less than three miles from the Naval Observatory. “I know you’re not fine, Hunter,” Biden said. “You need help.”

That encounter, which Hunter said he worried could lead to a physical confrontation, led to a trip to rehab that briefly got him back on his feet. “Dad saved me,” he wrote. “He never let me forget that all was not lost. He never abandoned me, never shunned me, never judged me, no matter how bad things got.”

Hunter blames the Obama administration’s ethics standards for derailing his lobbying career, but he later made business deals that left the impression he was trading on his father’s influence.

He seems aware that Biden’s connections helped him — “There’s no question my last name was a coveted credential,” he writes — even as he insists that his accomplishments should stand on their own. He expresses no remorse for his decision to join the board of Burisma as his father was overseeing foreign policy in the area — saying he wouldn’t do it again, only because it allowed the Trumps to use it against the Bidens.

In the final weeks before the 2020 election, a hard drive from a laptop said to belong to Hunter surfaced in a repair shop in Wilmington, Del. The owner said Hunter dropped it off and never retrieved it.

In interviews, Hunter has said that he doesn’t know whether the laptop was his or not. He insists that he doesn’t remember dropping a laptop off at the repair shop and isn’t aware of such an item going missing, but also admits that his memory from that period is hardly reliable.

“I wasn’t keeping tabs on possessions very well for about a four-year period of time,” he told CBS. Asked if it could be his laptop, he said, “Of course, certainly.”

Hunter Biden’s current chapter began in 2019 when he met Melissa Cohen, a South African film producer, on a blind date. At the time, Hunter was using drugs, moving from one dismal hotel to another in California and ignoring calls from his father and daughters.

After an hour, he and Cohen proclaimed their love to one another. A week later they were married. A year later they had a son, named Beau.

When Joe Biden found out about the relationship, he told Cohen, “Thank you for giving my son the courage to love again,” Hunter recounted on “Jimmy Kimmel Live.” It was the same thing Biden’s own mother told Jill Biden when they got married, five years after the death of Biden’s first wife.

Now, Hunter rents a $2.5 million home in Hollywood Hills, Calif., using a pool house as an art studio. He moved his voter registration to California in time to vote for his father in the Democratic primary there, and he’s been spotted several times at the White House.

He wakes up these days with 1-year-old Beau. He makes coffee and paints in the mornings. He and his wife go for walks and drives.

“I feel like I’ve returned to my authentic self,” he writes, in a letter to his brother Beau published in the book. “It’s all part of a new chapter, a new step in the process. I still have a ton of work to do on myself, with addiction, and clearing the wreckage of my past. I’m trying to make good on my debts — both figurative and literal.”

But while the hunger for drugs is gone for the moment, he writes, the peril always lurks: “I’m constantly aware of how much danger I’m in no matter how far away I get from my last drink or drug.”

Alice Crites contributed to this report.