SPRINGFIELD, Mo. - A cell phone was pressed to Sen. Barack Obama's ear as he slouched down in a black leather chair in the front cabin of his campaign airplane. He leaned away from the headrest, where his name is spelled out in blue stitching.
A few miles away, thousands of people streamed into JFK Stadium at Parkview High School for a late-night rally on Saturday. But Obama stayed on his chartered Boeing 757 as he spoke by conference call to thousands of his team leaders around the country, the volunteers who form the ranks of an army that he hopes will give him an edge in the waning hours of the presidential race.
As he pressed his right hand to his forehead, his sober expression seemed at odds with the confident gleam in the eyes of his advisers. While Obama smiles less than he once did, gauging his mood simply by looking at him is risky with a man whose flat-line temperament has seldom spiked along the rocky points of his journey.
In a campaign where he has slogged through more competitive Election Days than any recent nominee, only one more lies ahead. And it is the long path of the Democratic primary, which lurched from the ups of Iowa to the downs of Ohio, that his friends say provided Obama with a steady equilibrium as he enters this final turn in the race for the White House.
"As painful as the primary season was and how agitating it could be, it turned out to be a blessing for him," said Eric Whitaker, a longtime friend from Chicago who joined Obama aboard the crowded campaign plane for the last three days. "But my role now is to keep him loose. There's a lot going on in his world."
The lines in Obama's face have grown a bit deeper since he started his campaign, with the notches of gray hair along his temples more pronounced. He often looks exhausted, but flying the other night to Nevada, where he arrived after midnight, Obama passed on the chance to take much of a nap.
Instead, he walked around the cabin of his airplane, which is about the size of a bedroom, and talked about a favorite diversion - the coming basketball season - as he took care not to step on a senior foreign policy adviser, Mark Lippert, who was asleep on the floor.
In the last days on the trail, he is finishing Ghost Wars: the Secret History of the CIA, Afghanistan and bin Laden, and taking an occasional glance at US Weekly. He reads at least two newspapers a day, vigilantly checks his BlackBerry for updates on early-voting tallies and browses briefing books.
"In a marathon, when you are on mile 20 you start getting tired, but when you are on mile 25 you don't," said Lippert, who has grown familiar with Obama's travel rhythms while accompanying him on the four foreign trips he has taken since becoming a senator. "That's where he's at."
Whatever emotion he feels as his candidacy draws to a close, he displays little of it, either in public appearances or private conversations with his close advisers. The air of confidence that he exudes, which some critics castigate as arrogance, grew in part out of the primary, when he worked to avoid perceptions that he was weak or not ready.
But now, he is described by friends as feeling as though he has been thoroughly tested and is prepared to take on the job he has spent 22 months fighting for. Still, it is hard for even those closest to Obama to fathom what these days are precisely like, even for the imperturbable - often inscrutable - senator from Illinois.
His world is awash in powerful, conflicting emotions: the realization, presumably, that he may be about to become president; the huge optimism that he has unleashed, evident in the crowds he is drawing (and something he has told aides worries him a bit, given the expectations set for him); the weighty thinking he is gradually giving to how he would staff a government and deal with a transition in such a difficult time. All of this is taking place at a time where the woman who played a large role in raising him, his grandmother, is approaching death.
"What if I disappoint people?" Valerie Jarrett, a close friend and adviser, recalled Obama asking at several points throughout the campaign. "That's what gives him the energy to keep getting up every day."