He has suffered profound personal tragedy and seen his earlier political ambitions thwarted, but veteran Democrat Joe Biden hopes his pledge to unify Americans will deliver him a successful presidency after nearly half a century in Washington.
Rarely has the profile of opposing presidential nominees differed so sharply as in the 2020 race, which pitted the brawling President Donald Trump - the billionaire businessman who insists he remains the outsider - against the more seemingly empathetic Mr Biden, who has decades of political leadership experience and a blue-collar upbringing.
Mr Biden has run for president twice before, but the optimist from Delaware maintains this time he can shift the tone in America from anger and suspicion to dignity and respect.
"We can put an end to this presidency that has from the very beginning sought to divide us, to tear us apart," he said in Pennsylvania ahead of the polls opening.
"We can put an end to a presidency that has failed to protect this nation ... an end to a presidency that has fanned the flames of hate, poured gasoline on every opportunity he had all across this nation."
On Sunday morning, Australia time, the Associated Press called the state of Pennsylvania for the Democratic candidate, giving him the 270 Electoral College votes he needed to win.
At 77, Mr Biden will become America's oldest ever president.
He inherits a coronavirus pandemic that shows no signs of abating and an office he believes has had its credibility shattered by who he calls the "liar" Mr Trump.
Democratic presidential nominee Joe Biden has edged closer to winning the White House, expanding his narrow leads over Donald Trump in battleground states. Source: Getty Images
He no longer cuts the same figure he did during his eight years as Barack Obama's vice president. Though his smile remains, Mr Biden's gait is more delicate and his fine white hair thinned.
Opponents, and even some Democrats, wondered whether Mr Biden, who has been known to be gaffe-prone, would stumble in his long campaign against Mr Trump. The 74-year-old Mr Trump regularly calls him "Sleepy Joe" and accuses him of diminished mental acuity.
But Mr Biden has shrugged off the attacks, and in a flash of frustration with the relentlessly interrupting Mr Trump during their first debate, at one point told the president to "shut up."
A loss to him, Mr Biden said recently, would mean he was a "lousy" candidate and would have certainly lowered the curtain on a prolific if ultimately unfulfilling political career.
Mr Biden hit the national stage at just 29, with a surprise US Senate win in Delaware in 1972.
But just one month later, tragedy struck: his wife Neilia and their one-year-old daughter Naomi were killed in a car crash as they were Christmas shopping.
Mr Biden's two sons were severely injured but survived, only for the eldest, Beau - who later became attorney general of Delaware - to succumb to cancer in 2015 aged 46.
Biden won his first senate race at 29 years old. Source: Getty Images
It's been said that the tragedies have helped nourish the empathy Mr Biden shows in interactions with everyday Americans, whether that's smiling with college students, commiserating with unemployed Rust Belt machinists, or delivering a fiery admonishment of rivals.
But his personable side was curtailed by COVID-19 bringing in-person campaigning to a halt in March and has prompted a more cautious Mr Biden on the trail.
Humble roots and a stutter
Joseph Robinette Biden Jr was born 20 November 1942 and raised in the rust belt town of Scranton, Pennsylvania, in an Irish-Catholic family.
His father was a car salesman, but when the city went through tough times in the 1950s and he lost his job, he moved the family to neighbouring Delaware when the future president was 10.
"My dad always said, 'Champ, when you get knocked down, you get back up,'" Mr Biden says.
He made Delaware his political domain. As a young man he served as a lifeguard in a majority-black neighbourhood, an experience he said sharpened his awareness of systemic inequalities and strengthened his political interest.
He studied at the University of Delaware and the Syracuse University law school, and has expressed pride that he is not a product of the elite Ivy League.
He touts his working-class roots and recalls being hampered as a child by a stutter so bad he was cruelly nicknamed "Dash."
But he overcame the condition, and on the campaign trail has spoken about how he still counsels youngsters who stutter.
Barack Obama presenting the Medal of Freedom to Joe Biden. Source: Getty Images
Elected one of the youngest senators ever, he spent more than three decades in the upper chamber before serving eight years as Mr Obama's deputy.
Mr Biden's message is built largely on his association with the still-popular Mr Obama and on his ability to do business with the many world leaders who his former boss sent him to meet. "I know these guys," he often reminds people.
He offers moderate politics in a divisive time, but he has pledged to take progressive action as president, on climate change, racial injustice and student debt relief.
Mr Biden almost did not make it this far. Despite being the favourite of the Democratic establishment, he was deemed by some to be too old or too centrist.
His campaign looked like it was headed for disaster after disappointing primary losses to the fiery Bernie Sanders early this year.
But Mr Biden came roaring back in South Carolina's primary on the strength of overwhelming backing from African-American voters, a crucial base of Democratic support.
Biden lost early voting states in the primary before mounting a comeback. Source: Getty Images
Clinching the nomination marked a sharp contrast to his 1988 flameout when he quit in disgrace after being caught plagiarising a speech by British politician Neil Kinnock.
In 2008 he hardly fared better, dropping out after mustering less than one per cent of the vote in Iowa's.
That year he was ultimately picked as a running mate by Mr Obama, who dubbed him "America's happy warrior".
After their victory, Mr Obama quickly assigned Mr Biden to oversee the economic recovery during the last recession.
The two men differed over Afghanistan at the front end of Mr Obama's first term, with Mr Biden opposing a 30,000-troop "surge".
No perfect president
As a senator for more than 30 years, Mr Biden was known to forge unlikely alliances, and, like Mr Trump, he developed a lack of fidelity to script.
He faced a reckoning among Democrats, including Kamala Harris, who would become his running mate, for associating with known segregationists in the Senate and, in the midst of 1970s desegregation, for opposing "busing" policies aimed at transporting black children to predominantly white schools.
Joe Biden's son Hunter has been a figure of controversy. Source: AP
He also caught flak for helping draft a 1994 crime bill which many Democrats believe drove up incarcerations, disproportionately affecting African Americans. Mr Biden recently called the push a "mistake".
Other Senate episodes also threatened to spoil his presidential campaign: his 2003 vote for the Iraq war, and his chairmanship of controversial hearings in 1991 in which Anita Hill accused Supreme Court nominee Clarence Thomas of sexual harassment.
Last year he faced a storm over his own notoriously tactile approach with female voters that could suggest a man out of step with his modernising party. He apologised and promised to be more "mindful" of women's personal space.
Mr Biden met his second wife, teacher Jill Jacobs, in 1975 and they married two years later. They have a daughter, Ashley. He often points to Jill, 69, as a powerful asset for his campaign, and recalled recently how she took over as mother to her husband's two boys.
"She put us back together," Biden has said.
Joe Biden with wife Jill and daughter Ashley. Source: Getty Images
But his strong family ties have featured negatively during the campaign, with the revelation his son Hunter Biden received a lucrative salary serving on the board of a Ukrainian gas company accused of corruption while his father was vice president.
Mr Trump's push for Ukraine to investigate the Bidens led to the president's impeachment last December by the Democratically-controlled House of Representatives, but he was acquitted by the Republican-led Senate.
Hunter was not personally accused of any criminal wrongdoing, but Mr Trump hasn't let the issue die.
"It never goes away," Mr Biden said of the pain that lives within him since losing Beau. The tragedy prevented him from launching a presidential bid in 2016.
Even today, he often stops to greet firefighters, recalling that it was they who saved his boys.
They saved Mr Biden too. In 1988 firefighters rushed him to hospital after an aneurysm. Mr Biden's condition was so dire that a priest was called to give him last rites.
Nearly every Sunday Biden prays at St. Joseph on the Brandywine, a Catholic church in his affluent Wilmington neighbourhood.
There in the cemetery rest his parents, his first wife and daughter, and his son Beau, under a tombstone decorated with small American flags.
In January Mr Biden confided about Beau and his undeniable influence: "Every morning I get up... and I think to myself, 'Is he proud of me?'"
On Sunday he tweeted: "America, I’m honoured that you have chosen me to lead our great country".
"The work ahead of us will be hard, but I promise you this: I will be a president for all Americans — whether you voted for me or not. I will keep the faith that you have placed in me."