BOSTON, Massachusetts, July 29 (AFP) - Senator John Kerry's nomination for president is a tribute to his political grit and persistence, but questions remain whether the dour northerner has enough appeal to propel him to the White House.
A complex personality with a dogged ambition that was honed from an early age, the 60-year-old Kerry's patrician demeanour has, for all his hard efforts on the campaign trail, seen him struggle to fire up voter passions.
Supporters, however, highlight his intelligence and experience, gleaned from two decades in the US Senate, as well as his highly decorated military service in Vietnam.
Kerry's reserve has been acknowledged by the senator himself, attributing it in part to the formative years he spent in boarding schools in New England and Switzerland.
The product of a privileged New England background, Kerry lived the peripatetic lifestyle enforced on his family by his diplomat father's postings in Boston and Washington, Berlin and Oslo.
"I was always saying goodbye, and it steeled you," he told his biographer.
Born December 11, 1943 in Denver, Colorado, Kerry followed up his early education by attending a prestigious high school in New Hampshire and then Yale University, where he joined the secretive Skull and Bones club -- just as one George W. Bush would do several years later.
After graduating with a law degree in 1966, Kerry entered the military and like tens of thousands of other young American men was sent to fight in Vietnam.
It was to become a defining experience in his life and lead to his entry into politics, although his drift in that direction had begun much earlier when, as a teenager, he campaigned for his idol John F. Kennedy in the 1960 presidential election.
At one point, Kerry dated Jacqueline Kennedy's half sister and even went sailing with JFK.
As a Navy lieutenant in Vietnam, Kerry commanded a gunboat patrolling the Mekong Delta, earning three Purple Hearts along with his decorations for valour.
His military record has been pushed heavily by his campaign team, seeking to secure his credentials on the key issue of national security and also to draw comparisons with President Bush, who joined the Texas Air National Guard which did not see active duty in Vietnam.
On his return home, Kerry became an eloquent spokesman for Vietnam Veterans Against the War.
He helped organize a huge anti-war protest outside Congress in Washington in 1971, appearing alongside black militant Angela Davis and earning a place on president Richard Nixon's notorious "enemies' list."
That same year, 27-year-old Kerry testified before the Senate Foreign Relations Committee, earning headlines with his remark: "How do you ask a man to be the last man to die for a mistake?"
After a failed bid for Congress in 1972, Kerry served as a prosecutor in Massachusetts and went into private practice before he was elected lieutenant governor of the state in 1982.
Two years later he was elected to the US Senate. He has been re-elected three times since, though often overshadowed in the house by fellow Massachusetts Senator Ted Kennedy.
His Republican opponents have scoured his Senate voting record in order to highlight inconsistencies. Although sharply critical of US policy in Iraq, he voted for military intervention there.
Other opponents have questioned Kerry's championing of American blue-collar workers and the unemployed during his campaign, pointing to his privileged upbringing and marriage to multi-millionaire ketchup heiress, Teresa Heinz -- his second wife.
At 6 feet 4 inches (1.93m) with greying hair, a long face and undeniable gravitas, Kerry has been described as having a presidential air -- a respected if not hugely popular politician.