Joe Biden, the former US vice president, is seen by supporters as having the experience and appeal necessary to defeat Donald Trump. Photo / AP
Joe Biden has wanted to be president for at least 30 years. He first ran in 1988, crashing out in his bid for the Democratic nomination over a plagiarism scandal.
In 2008, Biden took on Barack Obama but again stumbled at the first hurdle, securing less than 1 per cent of the vote at the all-important Iowa caucus.
At the last election it was tragedy that intervened, with the then-vice president declining to run after his son Beau's death from cancer.
Now, with Biden the presumptive Democratic presidential nominee, one question looms large – is 2020 the year Biden finally gets over the line?
Fuelling his thinking, according to Larry Rusky, his communications director for both the 1988 and 2008 presidential bids, is a concern for where the country is heading under Donald Trump.
"Joe Biden has always believed in public service as a noble profession. I think it galls him immensely that Trump and others have tried to taint that," Rusky told The Telegraph.
"To the extent that he is driven, he's driven by a need to contribute to the relationship between the government and its people."
The appeal of Biden in the Age of Trump is clear, in the eyes of supporters. A senator for 36 years and a vice president for eight, he has the experience and authority that Trump lacks.
His record of deal-making, from helping pass an assault weapons ban while Senate judiciary committee chairman to negotiating Ukrainian ceasefires and budget deals as vice president, shows a bipartisanship lacking in the current White House.
Plus his uplifting rhetoric, inspiring back-story and Pennsylvanian roots prove he can win back the blue collar voters who flocked to Trump at the previous election.
That is certainly what Biden thinks, according to his recent memoir. He spelled out how his 2016 campaign would have been pitched around winning back the middle class – where Trump did so well.
His supporters argue that Biden has enough centrist clout to win back Trump voters while possessing sufficient left-wing credentials from the Obama years to inspire the Democratic base.
And it's not just backers.
"Eighty per cent of people I talk to on the Hill, both Republicans and Democrats, say Joe Biden has the best chance of beating Trump," said a UK official whose job it is to know.
Potential weaknesses
But for those hoping Biden is the Democrats' knight in shining armour, the list of weaknesses to his candidacy is not insubstantial.
There are the gaffes. From asking a wheelchair-bound politician to stand for applause to telling a largely black audience that Mitt Romney wanted to "put y'all back in chains", he developed a reputation for verbal slips while vice president.
It even has its own term, Bidenism, defined as a movement which practises "the art of committing public humiliation to themselves and other prominent public officials".
There is the baggage. In an anti-establishment moment, will US voters really go for the guy who has spent almost half a century at the heart of Washington's "swamp"?
Most recently, a number of women came forward with claims that Biden inappropriately touched them.
In response, Biden released a video in which he said "social norms are changing" and pledged to be "more mindful about respecting personal space in the future".
And then there is age. The former Delaware senator, four years older than Trump, would be 78 on inauguration date if he won – the oldest president ever elected for the first time.
Other concerns abound too. One former aide who worked on Biden's presidential bids but has since become disillusioned paints a downbeat picture of his former boss.
"I feel the media loves the soap opera of Joe Biden and never looks below the hood," said the ex-aide, who asked not to be named.
"Does he really have the network, the fundraising base, the talent to put forward a [successful] presidential bid?"
Family background
Away from politics, Biden's personal tragedies will unavoidably re-enter the spotlight if he runs for the presidency.
On December 18, 1972, just weeks after he first won a Senate seat, Biden's wife Neilia and one-year-old daughter Naomi were killed in a car accident.
Neilia's car struck a tractor trailer while the family was out Christmas shopping. Biden's sons, Beau and Hunter, were badly injured but survived the crash. Biden later remarried, having daughter Ashley with his wife Dr Jill Biden in 1981.
In August 2013, tragedy struck again when Beau, by then a politician himself talked of as a future presidential hopeful, was diagnosed with brain cancer. He would die two years later.
During that period, Biden continued his duties as vice president and shared emotional moments with Obama, the man who picked him as a running mate in 2008.
Biden recalls in Promise Me, Dad, his book about those years, how Obama once shed tears for his son and offered to personally pay for the treatment if money was short.
The pair's relationship, the most significant of Biden's political career, was so close in public that their "bromance" became a familiar joke before they left office.
Crazy Joe Biden is trying to act like a tough guy. Actually, he is weak, both mentally and physically, and yet he threatens me, for the second time, with physical assault. He doesn’t know me, but he would go down fast and hard, crying all the way. Don’t threaten people Joe!
However there had been tensions between 2008 and 2016 as their time in the White House switched from achieving in office to planning for what came next.
Biden made little attempt in his memoir to hide his frustration at Obama's repeated attempts to urge him not to run for the presidency in 2016, believing Hillary Clinton was better placed.
Friends and families describe Biden's upbeat outlook as key to his success.
"He's an optimist, but, you know, not in La-La-Land," his sister Val Biden Owens has said.
He is a car enthusiast, given a 1967 Corvette Stingray as a wedding gift by his father, and an American football player during his high school and college years.
Rusky, a friend as well as former political aide, suggests that Biden would have carefully weighed up a potential 2020 presidential bid.
"Assuming that the family is settled and he is feeling physically up for it, then it really comes down to doing the political equation," said Rusky, discussing what will be going through Biden's mind.
"Is his voice welcome in the debate? Is there space in the race? Is there a demand for his participation?"
Rusky said Biden will not let concerns about age stand in his way.
Once, before the 2012 election campaign, a friend quoted Pope John XXIII about "approaching old age" and suggested he take it easy.
Biden shot back with a quotation of his own, referencing the poet Dylan Thomas: "Do not go gentle into that good night. Rage, rage against the dying of the light."