BARACK Obama was asked during one of the many primary debates against Hillary Clinton what he considered to be his strengths. He replied: "I don't get too high when I'm high, and I don't get too low when I'm low."
It is this signature cool that the president-elect will bring to the White House, a sharp contrast to the straight-shootin' gunslinger image that President George Bush created.
Senator Obama's coolness under pressure is what has convinced many of the political commentators who have travelled with him across the nation during the past 1½ years that he has the temperament and the intellectual prowess to be president, even if he lacks the experience.
Even the death of his grandmother Madelyn Dunham, who raised him during his teenage years, did not seem to shake the determination of Senator Obama in the final days of the campaign.
It is this steeliness combined with his focus and determination that marked out Senator Obama on what he calls his "improbable journey".
His campaign has maintained a message of hope and healing the rifts in American society. For the most part, he has confined his critique of his opponent to his policies, without stooping to the personal.
It is an improbable journey that has inspired a nation that sees in Obama a physical embodiment of the egalitarian multiracial country that many would like to see America become.
His success is a powerful affirmation of the American dream: that with hard work and determination an American child can aspire to anything.
Senator Obama was born in Hawaii, the son of a white woman brought up in Kansas, Ann Dunham, and a Kenyan student, Barack Obama snr, who was studying economics at the University of Hawaii.
The marriage was brief. Barack senior headed off first to Harvard, then back to Kenya, leaving his son to be brought up by Ann and her parents.
Life was not easy and Senator Obama often mentions that his mother, who was completing her anthropology degree, had to rely on food stamps at times.
When Barack was four she married an Indonesian student, and moved to Jakarta with Barack, where he lived until he was nine. But then his mother, fearing he would grow up not knowing what it was to be American, sent him back to the US to live with the grandparents. He was accepted into a good school as part of a scholarship program.
Some of the most moving parts of Senator Obama's memoir, Dreams from my Father, deal with this period of return to America and grappling with his identity of being a black teenager and young man in a largely white environment.
He talks also of the pain of not knowing his father, of the awkwardness he felt in their one meeting when Barack was 10 and the regret he felt when he learned his father had died before he could travel to Kenya to reunite with him.
He talks about how he nearly fell into "exaggerated stereotypes of black male behaviour" and how he tried marijuana and cocaine, before deciding to focus on his studies by moving to Columbia University.
It was then that the determined Obama was born, but it might always have lurked there, instilled by the determination of the two women in his life, his mother and his grandmother.
At 24, after finishing his undergraduate degree, he went to work as a community organiser on the south side of Chicago.
He has retooled those grassroots skills into one of the slickest campaign machines seen in American politics.
The campaign's hallmark is its ground operations that have led to huge increases in voter registrations among Democrat voters and an impressive army of volunteers.
The Republicans have mocked Senator Obama's community organiser experience, but it is likely to be central to his approach to the presidency.
"He's a huge believer in the power of the bully pulpit ," says Brookings senior scholar, Tom Mann. He is likely to use his formidable powers of persuasion to drive changes in thinking in both America and on the international stage, he says.
In his memoir, Senator Obama tells multiple anecdotes of trying to mobilise desperate communities to take a greater part in fighting for their communities. There were some successes but even he admits, not many.
But the powers of conciliation he had learned on the south side served him well in the next chapter of his life, at Harvard Law School and later in politics.
As a first-time senator, he is one of the most junior in the chamber. For many including his rival for the nomination, Hillary Clinton, it seemed to be an audacity that he would seek the presidency now.
Obama justifies his impatience by drawing on Martin Luther King's phrase, "the fierce urgency of now". He believes that political times require a bold leader who can unite the country - and perhaps the world.