Aug. 25 (Bloomberg) -- Barack Obama's coolness cuts both ways.

Before Obama's March 18 race-relations speech, top adviser David Axelrod went to sleep unsure what the candidate would say the next morning. When a restless Axelrod awoke at 2 a.m., the entire speech, written by Obama, was waiting on his Blackberry.

``I thought, how could a guy operating under this kind of pressure, three hours of sleep a night, produce that kind of speech?'' Axelrod says.

That's one side of cool. There's another, one that can verge on cold.

Last August, the Democratic presidential candidate got a surprise endorsement from Zbigniew Brzezinski, the national security adviser under President Jimmy Carter, boosting Obama's foreign-policy credentials. The next month, the campaign enlisted Brzezinski to introduce him at an event in Iowa.

Then, before the March 4 Ohio primary, Obama spoke privately with a group of Jewish leaders in Cleveland and dismissed any formal association with Brzezinski, who's seen by some as too critical of Israel. ``He's not one of my advisers,'' Obama said. ``I've had lunch with him once.''

For the Illinois senator, cool can be complicated. It helps him maintain composure as he bursts through the barriers of race and politics; it also creates about him an aura of detachment. It fuels his boldness as well as his caution, the inspiration and the calculation, the intelligence and the ambition that will make him this week the first black presidential nominee of a major U.S. party.

Taking Risks

While Obama, 47, has profited from no small measure of luck, it is his willingness to take risks -- seizing opportunities for advancement as soon as they have presented themselves -- that made his triumph possible. The man who titled his best-selling memoir ``The Audacity of Hope'' has benefited far more from audacity.

The soaring quality of his message of ``hope'' and ``change'' propelled him to the nomination, its vagueness both a strength and weakness. The challenge of the Democratic convention and the campaign might well be how he fills in the canvass.

Obama has shown an ``enormous ability to arouse the intense admiration and affection of his base,'' says Sean Wilentz, a history professor at Princeton University. ``Exactly what he means by change, hope and transformation -- all the sort of big-payoff words that appear in his speeches -- he has yet to clearly define.''

A Global Celebrity

One reason may be his limited time in the public arena. There's no modern American precedent for the rapid trajectory of his career, which has made him that rare politician who's also a global celebrity.

Obama is the first nominee of a major party in more than a half-century whose life wasn't shaped by World War II, Vietnam or the struggles for racial and gender equality of the 1960s. He is the first to have such an exotic biography, the son of a white woman from Kansas and a black man from Kenya who grew up in Hawaii and Indonesia and has relatives on four continents.

His barrier-breaking candidacy also came at a price: It ended the hopes of those who wanted to see Senator Hillary Clinton of New York become the first woman to lead a major- party ticket. Though polls suggest Obama has captured some of her supporters, others remained unconvinced.

Bridging Generations

On the other hand, his candidacy has bridged some generational divisions. Robert Rubin, Treasury secretary under President Bill Clinton, initially supported Senator Clinton, while his son, Jamie, raised money for Obama. The father is now backing Obama too.

He also bridged a generational divide with his choice of Delaware Sen. Joe Biden, 65, as his vice-presidential running mate. The campaign hopes Biden will help inoculate Obama from criticism of his lack of foreign-policy experience, while helping him reach out to working-class voters who favored Clinton in the primary.

Obama needs no such help among younger voters: His pull among them has earned him credentials as a digital-age candidate, harnessing the power of the Internet to greater effect than any rival to build a network of 2 million donors and raise a record $390 million as of July 31.

What kind of president he would be and how he'd make decisions are among the questions Obama will begin to answer with the convention, which begins today in Denver. Already, his policy shifts on issues from federal wiretapping legislation to Social Security taxes to election financing have led even some Democrats to question the firmness of his convictions.

The Bottom Line

Obama so far has picked his battles carefully, choosing most often to focus on winning converts. ``One of the dangers here is that in the effort to constantly adjust his position, people then begin to wonder where his bottom line is,'' says Leon Panetta, President Clinton's former chief of staff. ``He's got to show that he's got a bottom line and that he's willing to fight for it.''

His visits last month to Afghanistan, Iraq, the Middle East and Europe, testing the world's embrace of him as a potential president, drew crowds that peaked at 200,000 in Berlin. The positive reviews weren't limited to non-Americans.

`He Was Superior'

``I've been in meetings with at least three different presidents,'' says Dennis Ross, the former Middle East envoy for Presidents George H.W. Bush and Clinton. ``He wasn't just up to the level, he was superior.''

When ``Obama met with the Palestinians, some came up afterwards and were saying that they were so impressed because here was Obama, who had the same facility, the same grasp of the issues as Clinton did,'' says Ross, who accompanied the candidate. ``And Clinton had been president for a few years by the time he met with them.''

Still, if Obama isn't easy to define for many Americans, that may be attributable to his unconventional life story. After his years in Hawaii and Indonesia, he attended Occidental College in Los Angeles before transferring to Columbia University in New York. He spent time in Chicago as a community organizer before heading off to Harvard Law School. He returned to Chicago to teach constitutional law and work as a civil- rights lawyer.

His varied experiences have given him a capacity to deal with many different types of people. He rose to be the first black president of the Harvard Law Review by winning over conservative classmates, then ran the journal in a way that appeased them and liberals alike.

No Demonizing

There was ``no question that he was a liberal, as were most editors of the Review and most students at Harvard Law at that time,'' says Brad Berenson, an associate White House counsel under President George W. Bush and a conservative lawyer in Washington who was an editor during Obama's tenure at the journal. ``But he wasn't the kind who demonized conservatives or personalized politics.''

That approach carried over later into his work in the Illinois legislature, where he ingratiated himself with Republican lawmakers. In Washington, Obama, who has one of the Senate's most liberal voting records, made alliances with Republicans such as Senators Richard Lugar of Indiana and Tom Coburn of Oklahoma, one of the chamber's most conservative members.

In the nation's capital, Obama became known as a good listener.

Even in gatherings with some of the country's top business leaders, he ``doesn't sit down to convince them how smart he is,'' says former Commerce Secretary Bill Daley, a supporter who attended a July meeting Obama held with advisers, including Robert Rubin and Warren Buffett.

Making the Arguments

``I've heard him say, `I just don't agree with you, I think there's a different way to look at this,' and then make the intelligent arguments that he needs to make,'' Daley says.

For his part, Obama said in an interview last month that ``I'm a big believer in a management style that focuses on getting the job done and doesn't focus on personal ambitions or personal hang-ups.''

If something doesn't work, ``you cut your losses and move on,'' he said. ``Learn from your mistakes and then try something else.''

`No-Drama Obama'

His generally temperate demeanor has earned him the nickname ``No-Drama Obama.'' Says Berenson, ``He always projected a kind of cool and a kind of reserve that masked the ambition that clearly had to be inside.''

That ambition, though, has rarely been far from the surface.

In 1996, when Obama first sought public office as a state senator, he worked to disqualify the woman he sought to replace, Alice Palmer, by challenging her nominating petitions. Palmer endorsed Hillary Clinton for the presidential nomination, making her an exception to Obama's tendency to cultivate onetime foes as allies.

Less than four years into his tenure in Springfield, Obama ran for Congress, challenging incumbent Representative Bobby Rush, a onetime Chicago alderman and, earlier, a member of the Black Panthers, a 1960s radical group that promoted black power and self-defense. Rush crushed him, and Obama was stung by the defeat.

He sought the counsel of Emil Jones, the Illinois state Senate president, whom Obama depicts in his first book as a tool of the Chicago political machine. Jones, who became his mentor, says the loss to Rush taught Obama a lesson in the need to build a solid coalition.

Beer and Cigarettes

Obama cultivated relationships in Springfield, sipping beer and smoking cigarettes -- hoping his wife, Michelle, wouldn't find out about the smoking. State Senator Terry Link, who hosted a weekly poker game, recalls Obama putting out his cigarette when his wife telephoned.

``We said, `What the hell is she going to do? See you smoking?''' Link says.

In 2004, Obama challenged both a multimillionaire and the son of a Cook County politician for the Democratic U.S. Senate nomination. Few thought initially that he had a chance. But the wealthy candidate, Blair Hull, who contributed $28 million from his personal funds toward his race, was undone by allegations of spousal abuse, and the other contender faltered. Obama won the nomination.

In the general election, his Republican opponent was to be Jack Ryan, a former investment banker who taught in the inner city and whose own celebrity looks were a match for Obama's. But Ryan's candidacy, too, was derailed by personal scandal; Illinois Republicans eventually had to import a candidate from out of state, one-time presidential candidate Alan Keyes, who moved from Maryland to make the race.

Electrifying the Convention

That summer, Senator John Kerry of Massachusetts, the Democratic presidential candidate, asked Obama to be the keynote speaker at the party's national convention in Boston. The speech electrified the crowd and helped Obama deliver a crushing defeat to Keyes that set him on the path to political stardom.

Crowds gravitated toward him. So did Senate colleagues: In the 2006 congressional elections, he was the No. 1 draw for Democratic candidates, often attracting thousands of people.

Then, just two years after he entered national office, Obama made his most audacious political leap: He announced his candidacy for president in front of the Old State Capitol in Springfield, challenging Clinton.

Formidable, Not Inevitable

``I think he always thought she was formidable; I don't believe he ever thought she was inevitable,'' says senior adviser Robert Gibbs. ``When he walked out on that stage in Springfield, he thought he would not just be nominated, but that he would be president.''

Symbolism has never been lost on Obama, from that announcement, where Abraham Lincoln gave his ``House Divided'' speech, to his Aug. 28 acceptance address -- which will come on the 45th anniversary of Martin Luther King Jr.'s ``I Have a Dream'' speech.

Former Dallas Mayor Ron Kirk, the first black person elected to that office, recalls telling his wife that Obama ``could be the Tiger Woods of politics because of his unique background, the way he was raised, the fact he is biracial. He represents the best of so much of what we have hoped for.''

Obama is ``doing more than winning the presidency,'' Kirk says. ``He's changing the political paradigm.''

At least that's what Obama is counting on. Even with a sour economy, an unpopular war and an even more unpopular Republican president, he remains deadlocked in polls with Republican candidate John McCain. Colleagues and opponents across the Senate aisle say they have little doubt he is both accustomed to the battle ahead -- and ready for it.

Even so, he knows there are times when it's wiser to back down. Harvard Law Professor Charles Ogletree recalls one such occasion: when Obama, in his last year at Harvard, organized a basketball game between black law students and prisoners.

Before the game, Obama went over to embrace the opposing team's center, and asked why he was incarcerated.

``The answer was double murder,'' Ogletree says, laughing. ``Although he tries to deny it, it was the worst game Obama ever played. He didn't shoot, and he let the prisoner have as many open shots as possible.''

To contact the reporters on this story: Julianna Goldman in Denver at jgoldman6@bloomberg.net; Kim Chipman in Chicago at kchipman@bloomberg.net.

Last Updated: August 24, 2008 19:01 EDT