Joe Biden - a fixture in US politics for a half century as a senator and vice president - has completed the long climb to the political mountaintop that includes two previous failed presidential bids.
All the major US media outlets are now projecting a Biden victory over Donald Trump.
Photo: AFP
When he is sworn in as the 46th president on 20 January 2021, the Democrat from Delaware will be 78 and will become the oldest person ever elected to the White House.
Biden has sought to portray his political experience as a benefit, casting himself as a tested leader up to the tasks of healing a nation battered by the coronavirus pandemic and providing steadiness after the turbulence of Trump's presidency.
Accepting the Democratic presidential nomination in August, Biden stressed compassion and decency, seeking to draw a contrast with the pugnacious Trump.
"I'll be an ally of the light," Biden said, "not the darkness."
Biden unsuccessfully sought the Democratic presidential nomination in 1988 and 2008 before finally securing his party's blessing this year with strong support among black voters.
He brings to his political career a mix of blue-collar credentials, foreign policy experience and a compelling life story marked by family tragedy - the loss of his first wife and a daughter in a car crash, and a son to cancer.
Blue-collar background
Joe Biden Photo: AFP
Joseph Robinette Biden Jr was born in the blue-collar city of Scranton, Pennsylvania, the eldest of four siblings. His family later moved to Delaware. Biden overcame stuttering as a boy by reciting passages of poetry to a mirror.
He attended the University of Delaware and then law school at Syracuse University.
He was practically a political novice - having served two years on a county board in Delaware - when in 1972 he became the fifth-youngest elected senator in US history.
Biden was just 29 when he was elected to represent Delaware in the US Senate where he remained for 36 years.
Family tragedy mars early days in politics
Just a few weeks after his Senate election, his first wife, Neilia, and their 13-month-old daughter, Naomi, were killed in a car crash.
He almost abandoned his political career to care for his two young sons who survived the accident but stayed on, commuting by train from Delaware to Washington to avoid uprooting them.
Despite years of partisan hostilities in Washington, Biden remained a believer in bipartisanship. During his time in the Senate, he was known for his close working relationships with some of his Republican colleagues.
However, he was criticised as chairman of the Senate Judiciary Committee in 1991 for his handling of sexual harassment accusations against Republican President George H W Bush's conservative Supreme Court nominee Clarence Thomas by former aide Anita Hill. Liberals criticised him for doing too little to defend Hill's allegations, which Thomas had denied.
Joe Biden brings a mix of blue-collar credentials, foreign policy experience and a compelling life story marked by family tragedy to the US's top job. Photo: 2020 Getty Images
The committee held explosive televised hearings prior to Thomas's eventual Senate confirmation.
The hearing was conducted by an all-white, all-male panel, and several women apparently willing to back up Hill's account were not called by Biden to testify.
Speaking in a TV interview in April 2019, Biden said that he was "sorry for the way she got treated".
One of Biden's accomplishments as a senator was helping to secure passage in 1994 of a law called the Violence Against Women Act to protect victims of domestic crimes.
While in the Senate, he built up a specialty in foreign affairs and at one time headed the Foreign Relations Committee.
He voted in favour of authorising the 2003 Iraq invasion before becoming a critic of Republican President George W Bush's handling of the war.
Former president George W Bush with Joe Biden during a bipartisan meeting with Congressional leaders at the White House in July 2001. Photo: AFP
Accused of plagiarism
Biden's first two presidential runs did not go well. He dropped out of the 1988 race after allegations that he had plagiarised some speech lines from British Labour Party leader Neil Kinnock.
Joe Biden, with his second wife, Jill, alongside, announces he is dropping out of the 1988 presidential race. Photo: AFP
In 2008, Biden won little support and withdrew, only to be selected later that year as Barack Obama's running mate.
Special relationship with Obama
After leaving the Senate he served from 2009 to 2017 as vice president under Obama, the country's first black president.
Working alongside Obama, Biden served as a troubleshooter on matters of war and foreign affairs and on domestic issues such as gun control and fiscal policy.
The president did not always heed Biden's advice. Obama gave the go-ahead for the 2011 raid in Pakistan that killed al-Qaeda leader Osama bin Laden despite Biden's warning that it was too risky.
However, the pair established a close working relationship in which Biden frequently called Obama his "brother".
Photo: AFP
In a surprise ceremony in the final days of his presidency, Obama awarded Biden the Presidential Medal of Freedom - the nation's highest civilian honour.
"To know Joe Biden is to know love without pretence, service without self-regard and to live life fully," the then president said.
An emotional Joe Biden receives the US's highest honour from then president Barack Obama. Photo: AFP
Battle for 'soul of the nation'
Biden opted not to run for president in 2016, only to watch Trump defeat Democrat Hillary Clinton. When Biden announced his 2020 candidacy in April 2019, he took aim at Trump.
"We are in the battle for the soul of this nation," Biden said, adding that if re-elected Trump would "forever and fundamentally alter the character of this nation - who we are - and I cannot stand by and watch that happen".
Biden selected Senator Kamala Harris - whose father is an immigrant from Jamaica and whose mother is an immigrant from India - as his running mate, making her the first black woman and first person of Asian descent on a major-party US ticket. At 56, Harris is a generation younger than Biden.
The folksy Biden, known for blunt talk and occasional verbal gaffes, has often referenced his working-class roots to connect with ordinary Americans. Biden also was the first Roman Catholic US vice president.
In 2015, his son Joseph "Beau" Biden III, an Iraq war veteran who had served as Delaware's attorney general, died from brain cancer at age 46. Biden's son Hunter has struggled with drug issues as an adult.
Biden himself had a health scare in 1988 when he suffered two brain aneurysms.
Recent sexual assault allegations
In May this year, Biden denied a former Senate aide's accusation that he had sexually assaulted her in 1993, calling the claim "not true" and saying "unequivocally it never, never happened". The allegation was made by a California woman, Tara Reade, who worked as a staff assistant in Biden's Senate office for about 10 months.
Reade was one of eight women who in 2019 came forward to say Biden had hugged, kissed or touched them in ways that made them uncomfortable, though none accused him of sexual assault. Reade publicly accused him of the assault months later.
During this year's bitter presidential campaign Biden maintained the president's handling of the worsening coronavirus crisis was an "insult" to its victims.
"Even if I win, it's going to take a lot of hard work to end this pandemic," he said. "I do promise this - we will start on day one doing the right things."
On another occasion he promised: "I plan to unite the nation. I'm running as a Democrat but I'm going to be everyone's president."
- Reuters / BBC