Joe Biden bursts from twilight of career onto biggest stage

He has been scarred by tragedy and failed presidential runs, stumbles while speaking, and is 77. But that same backstory, coupled with unmatched Washington experience, is exactly what Joe Biden bets will win over Americans tired of his polar opposite -- Donald Trump.

If Trump brought brash and bombast to the White House, wrecking everything from convention to international treaties along the way, Biden offers reassurance.

Best known as the vice president under Barack Obama, he wants Democrats -- and maybe wavering Republicans -- to feel they can rewind to pre-2016.

With his white hair, well-cut suits and every bit the air of a longtime senator Biden is the fatherly or grandfatherly figure calming a nation on the verge of a nervous breakdown.

So while Trump derides him as "Sleepy Joe," Biden bets that after the Republican's turbulent reign, Americans wouldn't mind a bit of a rest after all.

Trump succinctly summarizes his politics as "winning, winning, winning."

Biden, who became presumptive Democrat nominee Wednesday after the withdrawal of Bernie Sanders, claims to be reaching for something deeper: "a battle for the soul of America."

LONG ROAD

Trump is 73, but Biden will turn 78 shortly after the November election, which would make him the oldest president ever to take office.

Elected one of the youngest senators in US history, then vice president for eight years under America's first black president, Biden is like living history.

Along with those successes have come humiliating flops, notably his 1988 and 2008 White House bids when he failed to win a single state primary.

Even this time, his run looked destined for disaster after losses to the fiery Sanders in Iowa, New Hampshire and Nevada.

But 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.

"For those who have been knocked down, counted out, left behind, this is your campaign," Biden declared.

HUMAN SIDE

Biden's message is built largely on his association with the still popular Obama and his moderate politics in a time of partisan divide.

But where he stands out among other Washington old-timers is in showing a painfully human side that contrasts starkly with Trump's all-conquering, never-doubting style.

Biden's first wife, Neilia Hunter, and one-year-old daughter, Naomi, died in a car crash in 1972 while Christmas shopping, just weeks after Biden had defied the odds and won election to the Senate from Delaware.

The accident left his two sons, Joseph "Beau" Biden III, 4, and Robert Hunter Biden, 2, badly injured, and the 30-year-old Biden was sworn in to the Senate beside their hospital beds.

Biden met his second wife, Jill Jacobs, a schoolteacher from Pennsylvania, in 1975 and they married two years later. They have a daughter, Ashley, born in 1981.

Both boys recovered from their injuries and Beau followed his father into politics, becoming attorney general of Delaware and contemplating a run for state governor before dying of brain cancer in 2015 at the age of 46.

For all of his elite Washington status, Biden's perseverance has struck a chord with many Americans in more humble jobs. On Wednesday, during an online Q&A with supporters, he returned to the theme, quoting Britain's World War II prime minister Winston Churchill: "If you’re going through Hell, keep going."

THE OTHER SON

Biden retells these family stories so often that, despite his obvious grief, they have become part of a political brand.

But his younger son Hunter is another matter.

With a checkered career as a lawyer and lobbyist, Hunter Biden got a lucrative salary serving on the board of a Ukrainian gas company accused of corruption while Biden was vice president.

Hunter Biden, who has admitted to alcohol and drug addiction, was never charged in any crime.

The Ukraine affair was at worst, Biden allies say, bad optics.

Trump, however, believed he'd found a candidacy-killing flaw. Last year, he pushed Ukraine's then new president, Volodymyr Zelensky, to investigate Hunter's past and sent his own lawyer, former New York mayor Rudolph Giuliani, on secretive dirt-digging missions.

It was this zeal that eventually led to Trump's impeachment on charges that he used his foreign policy powers to try and benefit his reelection campaign.

Trump calls the charges, which were thrown out by the Republican-led Senate, a "hoax."

But although the impeachment is now over and Ukraine has quietly moved on, declining to probe Hunter, Trump will undoubtedly weaponize the issue at every opportunity right up to election day.

'UNCLE JOE'

Joseph Robinette Biden Jr was born on November 20, 1942 and raised in Scranton, Pennsylvania, in an Irish-Catholic family. His father was a car salesman.

Biden touts his blue-collar roots on the campaign trail and recalls that he was hampered as a child by a stutter so bad he was cruelly nicknamed "Dash."

He overcame the condition and came to see it as a blessing that he said allowed him "insight into other people's pain."

As "Uncle Joe," he is known for his personal warmth and folksy manner. But he also has a propensity for public gaffes, and his often rambling delivery on the campaign trail has raised questions over his mental agility.

Biden's decades-long political career will make it easy for Trump to highlight errors and embarrassing moments, not least the Democrat's support for the now hugely unpopular Iraq war.

But longevity has also given Biden an advantage -- there are few skeletons left in the closet. And in a time of turmoil, his claim to experience may prove alluring.