INDEPENDENCE, Iowa — The doctors said Chuck Taylor’s quadruple bypass had gone about as well as it could go, so the next day, his wife, Patricia, thought it was safe to slip out for a pressing errand. Thirteen minutes after she pulled away, the hospital called: Chuck was dying.

As she mourned in the summer of 2014, condolences and flowers poured in from family, friends and fellow Democratic activists. Then one day she received a call from a private number and was startled to hear the voice of Vice President Joe Biden. The Taylors had never been big donors, “because we don’t have any money,” Patricia said. “We’re active in Democratic circles, but as far as being movers and shakers, we’re not.”

Yet during her first days without Chuck in more than four decades, Biden, whom she barely knew, spoke with her several times, often talking of his own losses. “He said, ‘I wish I could tell you that some day it will stop hurting,’ ” she recalled. “ ‘The days when you feel like you can’t go on will be further in between. But every day until you leave this Earth, you will miss him.’ ”

Perhaps more than any political figure since Robert F. Kennedy, who ran for president less than five years after his brother’s murder, personal grief is at the center of Biden’s public identity. It has bookended his career; his wife and infant daughter died in a car crash shortly before he entered the Senate in 1972, and his son Beau, a rising political star in his own right, died at age 46 of cancer in 2015.

As Biden crisscrosses the country trying to convince people that he should be president, he often encourages voters to reflect on their most difficult, grief-stricken moments — and his. In an age when so much of politics is about memes and tweets, blogs and GIFs, some voters say it humanizes Biden in a way that is not pierced by public gaffes or the attacks of his rivals.

Biden’s sorrow has emerged anew in recent weeks, amid questions about how he has handled the potential conflict of interest involving Hunter, his surviving son. Hunter served on the board of a Ukrainian energy company when Biden was spearheading Ukraine policy as vice president.

A State Department official told lawmakers recently that in 2015, when he contacted the vice president’s office about the potential appearance of a conflict in Hunter’s role, he was told Biden did not have the “bandwidth” to deal with it while Beau was battling cancer.

Biden is almost certain to continue facing such questions, and he has promised that if elected, no one associated with him will serve on foreign boards. For those who’ve forged a connection with Biden, such statements are not necessary. “I know the kind of man he is,” Taylor said.

Biden and his campaign declined to comment for this article.

The former vice president is hardly the only presidential candidate to try to humanize himself for voters, especially in states such as Iowa or New Hampshire, whose residents value their one-on-one interactions with candidates.

But no other candidate weaves grief into his personal message the way Biden does. He weeps when talking to audiences about his son. He calls and writes to bereaved voters. He asks crowds how many of them, or their relatives, have had cancer.

Biden’s associates acknowledge that he derives a political benefit from displaying his sadness so publicly and sharing his agony on the campaign trail. But that doesn’t mean the grief is not real, his supporters say.

“As they say, in politics, you’re always on — there’s no question about that,” said Sen. Doug Jones (D-Ala.), a friend of Biden’s. “But there’s a difference between being on, and being not sincere and giving a performance that’s not yourself.”

Jones added: “You want to say the right things. You want to make sure those people are persuadable voters who will understand you. But you really have to be you.”

When Biden appeared recently in Los Angeles at an event sponsored by the Service Employees International Union, neither attendees nor moderators raised the current impeachment furor, which arose from Trump’s efforts to get Ukraine to investigate Joe and Hunter Biden.

Instead, the moment that endured was Biden’s emotional reply to a woman who asked what he would do to improve the lives of home-health-care workers. Wiping away tears, Biden talked about the emotional roller coaster of caring for Beau.

“Eighteen months he lived, knowing he was going to die — nobody makes it,” Biden said, referring to the severity of Beau’s diagnosis. “I can’t imagine what I would have done were it not for the hospice workers.”

He continued crying as he wound health-care policy into the story of his own suffering. “Sorry. No. No. The president shouldn’t react that way,” Biden said. “But here’s the deal. I make you a commitment. I make all of you a commitment: I will protect your right to health care like it is my own family, because I understand.”

A few weeks earlier, at a town hall event in Laconia, N.H., it didn’t take long for a question-and-answer session to turn somber. “Raise your hand,” Biden told those in the crowd, “if you’ve lost a son or daughter, husband or wife, or you yourself are fighting cancer.” He continued: “Just look around. Almost everybody. More than 50 percent of every audience I say this in.”

His campaign book, “Promise Me, Dad” — which recounts how Beau urged him to run — is itself in part a meditation on sorrow and death.

“It amazes me how many people there are who endure and live with devastating loss with nowhere near the support I have had, who get up every single day, put one foot in front of the other, and simply carry on,” Biden writes.

He adds that he has “a long list of strangers who have my private number and an invitation to call. And many of them do.”

The campaign is showcasing Biden’s relationship with tragedy in a new way. But it’s been part of his public life for nearly a ­half-century.

After a swift rise that saw Biden elected to the U.S. Senate before he was 30, his wife and baby daughter were killed in 1972 when their station wagon was broadsided by a truck as they were shopping for a Christmas tree. Biden’s two sons were seriously injured.

Beau, who Biden has referred to as Joe Biden 2.0, died when his father was vice president. His other son, Hunter, has struggled with substance abuse for much of his adult life. Biden himself had surgery for two aneurysms in 1988.

In 2012, when Biden was addressing family members of service personnel killed in action, he paused to recall the death of his wife and daughter.

“For the first time in my life, I understood how someone could consciously decide to commit suicide,” Biden told them. “Not because they were deranged, not because they were nuts — because they’d been to the top of the mountain and they just knew in their heart they’d never get there again.”

He spoke of emotions like the “awful, awful, awful feeling of guilt” a survivor can have when he finds love after the death of a spouse. The speech prompted conservative columnist Michael Gerson to write of Biden, “Sometimes he seems to be the last genuine human being in American politics.”

Sen. Christopher A. Coons, a Democrat who occupies the Delaware seat once held by Biden — and who was consoled by Biden after his own father died — said the former vice president’s empathy is real.

“I have been with people where Joe Biden was not looking for their vote, could not ever be helped by them — complete strangers from other parts of the country at times when he was clearly not running again,” Coons said. “I’ve just been blown away that this guy took not just five minutes, but 45 minutes, with, like, a Republican from Alabama.”

Patricia Taylor does not need convincing. Before retiring, she was a parole officer, equipped with what she considers a well-honed internal lie detector. She is well aware that Biden is a politician, but as an Iowa voter she’s confident she can spot someone trying to manipulate her.

She says her talks with Biden were among her few bright moments during one of the darkest periods of her life. When Biden and his wife, Jill, sent flowers to Chuck’s funeral, she had them dried with silica and, a year later, spread the petals over Chuck’s grave.

Biden’s calls were not derived from some set of talking points provided by an aide, she said. “If he had an index card that gave him all the details of Chuck, I would have felt grateful as all get-out for just that,” Taylor said. “But he gave me a hundred times more than any politician would have given me. He gave me something that a caring human being would give me.”