Washington  - Arnold Schwarzeneggers jokes about his skinny" legs aside, Barack Obama, 47, enters the White House January 20 with the sort of political muscle and physical stamina that a US presidential campaign creates.

The presidential race usually takes 12 months. But the black senators pursuit of the presidency across 50 states nearly doubled the time as he wrestled with Senator Hillary Clinton, 61, over the Democratic nomination.

Either outcome would have been historic: The first African- American or the first woman to grasp a major party nod.

It was not only the longest presidential bid in US history, but also the most expensive. An estimated 1.7 billion dollars was raised by more than a dozen candidates from both parties, a 52-per-cent jump over the 2004 campaign and more than three times that spent in 1994, according to the Federal Election Commission.

The close party race held the public spellbound and excited 1960s social activists for whom the Democratic Party had been the crucible for black and female empowerment and who were bitterly divided between the two camps in 2008.

Duelling in endless televised debates, particularly between the tough former first lady and the black senator from Illinois, began at the unheard-of early date of June 2007.

Clinton`s insistent challenges to Obama were largely credited with building his rhetorical muscle for the general election race against Republican Senator John McCain, 72, the POW from Vietnam and long- time member of Congress.

There were many odds against an Obama presidency. He was inexperienced, with only four years on the national scene and no executive background. Would a country with such a deep history of apartheid elect a minority president? And with such intense female- versus-black divisions inside the party, could he unite the two?

The country was waging war on two fronts. Would voters choose a man like Obama, with no military background, over the war hero McCain?

Voters answered with a resounding "Yes" giving Obama one of the strongest wins in recent history: 52.8 per cent against McCain's 45.8 per cent. It was a clear rejection of eight years of Republican rule. President George W Bush's popularity ratings had fallen so low that he did not appear once on the campaign trail on McCain's behalf.

Still, coming out of the Republican convention, McCain pulled nearly even with Obama in the polls, riding the novelty of little- known Alaska Governor Sarah Palin as his vice presidential candidate.

If McCain had hoped that putting a woman on his ticket would attract disaffected Clinton supporters, he was wrong. After a brief time, Palin's often uninformed views became a liability. Some women voters were even insulted that McCain hadn't chosen a more qualified Republican woman.

Meanwhile, the full force of Obama's financial and organizational muscle emerged as he out-raised McCain 2-to-1, a turnabout for Democrats from past campaigns. Obama's team used the internet to enlist millions of new voters, sign up volunteers and expand his grassroots base.

Nearly half of the record 745 million dollars Obama raised came from donors who gave less than 200 dollars. For McCain, only one- fifth of his 350 million dollars came from a similar source.

In the final two months, Obama exuded presidential calm in tense debates with McCain, and as the US financial tsunami hit the world.

By November 4, US voters had decided for Obama, but not without a night of suspense over three key states. First Pennsylvania, then Ohio and finally Virginia, the heart of the old civil war Confederacy which had voted Republican for more than 30 years, fell to Obama.

Obama's win unleashed emotions. For days afterwards, tears welled up unexpectedly as strangers of all races discussed the outcome. Mainly, it was joy that the country had put its racist past behind it. But there was also a tinge of relief that the Bush years had ended and Americans could once again hold up their heads overseas.

"If there is anyone out there who still doubts that America is a place where all things are possible, who still wonders if the dream of our founders is alive in our time, who still questions the power of our democracy, tonight is your answer," Obama told the 270,000 people at Grant Park, Chicago after his victory.

Obama's new life at the White House will include wife Michelle, a Harvard-trained lawyer, and daughters Sasha and Malia, age 7 and 10. They will give the country regular glimpses of black middle class family life, to counter lingering racial prejudices about single black mothers and absent black fathers.

There will probably be a basketball court so Obama can keep up with his beloved sport, as he did nearly every day on the campaign trail.

California Governor Schwarzenegger, the body builder, joked at a McCain rally about Obama's "skinny legs" and urged him to do "bicep curls to beef up those scrawny little arms."

But after Obama's win, he conceded that perhaps he had something to learn about basketball from the future president. (dpa)