By Wesley Johnson, PA, in New York
John McCain's presidential campaign has been defined by a series of bold and risky moves by a man who hopes to become the oldest first-term president in United States' history.
The Arizona senator surprised the world when he picked Alaska governor Sarah Palin as his running mate. Less than one month later, Mr McCain announced he was suspending his campaign and called for the first presidential debate of the election to be cancelled so he could focus on the economic crisis engulfing the country.
But, in a sign that the move was starting to backfire, he backed down at the last minute and attended the debate despite the US Congress' failure to reach an economic agreement.
Then, as the bailout plan looked as if it was going to be passed, he bragged that he was an action-oriented Teddy Roosevelt Republican who did not sit on the sidelines at a moment of crisis.
"I went to Washington last week to make sure that the taxpayers of Ohio and across this great country were not left footing the bill for mistakes made on Wall Street and in Washington," he said at a rally in the key swing state.
It was not the only decision which critics described as risky. His choice of Mrs Palin, the mother-of-five who described herself as a pitbull with lipstick, injected a "breath of fresh air" into his campaign, and she helped energise the party's conservative base with her devout Christianity and pro-life views.
But it raised serious concerns over his judgment as the inexperienced state governor would become America's commander in chief should anything happen to Mr McCain - who is 72 and has a history of skin cancer.
The septuagenarian's rise through his party's hierarchy was a remarkable and improbable comeback after weeks of poor fundraising, significant staff departures, and falling poll numbers threatened to derail his campaign last summer.
He spent five-and-a-half years in a prisoner of war camp in Vietnam, refusing to be released until those captured before him were set free - in line with US policy.
He was on his 23rd bombing mission on October 26, 1967, when his plane was hit by a surface-to-air missile over Hanoi, north Vietnam.
He ejected, was knocked unconscious and broke both arms and his right knee.
Captured, he had his shoulder broken by a rifle butt and was bayoneted in the ankle and groin before it was revealed he was an admiral's son.
Nicknamed the "Crown Prince" by his captors, he received limited treatment for his injuries but was also tortured and beaten until he was near death on several occasions.
Today, he may shuffle slightly or hold his arms stiffly, is unable to raise his arms above his head and often requires assistance with brushing his hair or donning a jacket - all as a result of his half-decade as a PoW.
Mr McCain is seen as a temper-prone old-school Republican who staunchly supports the war in Iraq and believes the fight against terror will be central to the presidency.
But his out-of-favour views on issues such as Iraq and immigration led to many Republicans growing weary of his non-conformist impulses as he makes his second bid to be the leader of the free world.
Renowned for his relaxed candour, maverick flair and openness to bipartisan deals, Mr McCain often displays his humour and dry wit on the campaign trail.
Born on August 29, 1936, in Canal Zone, Panama, John Sidney McCain III was born into an illustrious military family.
Both his father, who led the Pacific forces in Vietnam, and his grandfather, who commanded aircraft carriers in World War Two, were four-star admirals in the US Navy.
A hot-tempered child, he went to private school before enrolling at the Naval Academy at Annapolis, Maryland, where he has been described as an "unabashed troublemaker", for his untidy room, unchecked tongue and taste for partying.
He married Philadelphia model Carol Shepp in 1965 after meeting her while training as a pilot in Pensacola, Florida, and adopted her two sons, Doug and Andy.
The following year the couple had a daughter, Sidney, and in January 1967, Mr McCain was promoted to lieutenant commander and within a few months was on his way to Vietnam.
Following his long physical rehabilitation after being freed from the Hoa Lo prisoner of war camp, dubbed the Hanoi Hilton, in 1973, Mr McCain was a changed man - raring to go after what he saw as a wasted six years of his life.
He continued in the navy but his marriage ran into difficulties. Mr McCain engaged in infidelities and eventually divorced Carol a month before marrying Cindy Hensley, of Phoenix - nearly 20 years his junior - in May 1980. They have four children, Meghan, Jack, Jimmy and Bridget.
He retired from the navy the following year and moved to his wife's home state of Arizona, where he began his political career.
After three years as an Arizona congressman, Mr McCain became a senator in 1987, where he directed his attention to defence and foreign policy. But that year, he was the only Republican involved in the Keating Five scandal - five senators who helped Arizona banking executive Charles Keating in his bid to keep federal regulators from taking action against him for questionable business practices.
The Senate ethics committee found he broke no laws, but he acknowledged bad judgment in attending two meetings with regulators and Senate colleagues on Keating's behalf.
Mr McCain's health may also become an issue as the campaign intensifies. An operation to treat a skin cancer called melanoma in August 2000 left a noticeable mark on the left side of his face and he often tells audiences he has "more scars than Frankenstein".
Despite his age, Mr McCain's experience and broad appeal to Republicans, Democrats and independents could unite a country in its time of need and serve him well in his second White House bid.
"I may not be the youngest candidate in this race, but I'm certainly the most prepared," he says. "And I'm prepared to lead this country. I don't need any on-the-job training. I'm ready to do the hard things. And that's what I intend to do."
