REDWOOD CITY, Calif. -- By the time President Obama took the stage at the Fox Theater here, he was in the 18th hour of a 19-hour day. His tie was still knotted to the top as he launched into his stump speech, attacking his opponent's record and defending his own. "I still believe in you," he said, "and I hope you still believe in me."
That is a proposition he is testing four years after the political winds converged behind his improbable journey to the White House. In marathon trips across the nation, he seeks to justify the faith supporters invested in him and earn it back. Sometimes he sounds like the outsider of 2008 running against an establishment that he now sits atop.
With Election Day five months off, the campaign increasingly appears to consume Mr. Obama's days and his White House, shaping his schedule, his message and many of his decisions. He is running against himself as much as Mitt Romney, or rather two versions of himself -- one the radical ruining the country conservatives see, and the other the savior of the country he promoted last time around and has struggled to live up to.
The protesters waiting outside a campaign fund-raiser in Denver last week were probably never supporters. But some of their signs cut close to the bone. "Out of Hope, Ready for Change," one read. "Obama's Blvd. of Broken Promises," said another.
As he blitzes battleground states, the president betrays no signs of self-doubt or worry even though his approval rating in New York Times/CBS News polls has exceeded 50 percent only once in two years. Like Bill Clinton and George W. Bush before him, he powers through adversity with defiant resolve, hoping to prove that the doubters underestimated him.
Flying on Air Force One last week, Mr. Obama read to aides a letter he had received from a 90-year-old man from Florida who said he was looking for work in sales and marketing. "I'm rounding third but not ready to slide into home," the man wrote the president. "This is the best letter of the day," Mr. Obama told the aides.
Last week started in Chicago, where Mr. Obama hosted a summit meeting of NATO leaders who agreed to end their guiding role in the combat mission in Afghanistan by next year. Showing how such official events have campaign overtones these days, the Afghanistan decision quickly became a talking point at fund-raisers later in the week. A speech after that on Monday in Joplin, Mo., hailed the need for a community to come together and its residents to help one another a year after the killer tornado there, the president's message implicitly repudiating a Republican philosophy that in other settings he dismisses as "you're on your own."
In a commencement address two days later at the Air Force Academy in Colorado, a swing state, Mr. Obama rejected fears of national decline, essentially rebutting the Republican argument that he does not believe in his country or its future. A half-dozen times he uttered the signature phrase "I see an American century" -- much as Mr. Romney has promised to deliver "an American century" in his speeches.
Each week brings more grueling travel. Mr. Obama left the White House just after 7 a.m. Wednesday for Colorado, the first stop on a two-day trip. Aides said he was behind where Mr. Bush and Mr. Clinton were at this point in campaigning, but they are ramping up his schedule.
During long hours on Air Force One, Mr. Obama sets himself up in the conference room as aides wander in and out. He reads briefing books; receives updates; checks in with his chief of staff, Jacob J. Lew, back at the White House; and flips through The New Yorker or Sports Illustrated. The television is often tuned to ESPN with the sound down.
His messages have an improvisational feel at times. On the flight to Colorado last week, Jay Carney, his press secretary, read him an online column concluding that he has presided over slower growth in federal spending than any president since Dwight D. Eisenhower. Mr. Obama liked it so much he inserted it into his campaign speech.
Just like that, an online column, rather than a detailed study by a budget office, became fodder for his argument. "Since I've been president, federal spending has risen at the lowest pace in nearly 60 years," he told supporters in a hotel ballroom in Denver. What he did not say is that the calculation did not count significant spending in his early months in office and assumed future cuts that he opposes.
The crowd of 550, fewer than the 700 expected, was obviously glad to see him, though the room at times felt a little flat and Mr. Obama a little tired. The audience laughed at his implicit gibes at Mr. Romney's wealth, like when he applauded Mr. Romney's "personal success" and when he prefaced a sentence by referring to "those of us who've spent time in the real world."
From there, the president flew to California, the cash cow for Democrats. His motorcade rolled through exclusive Atherton in the heart of Silicon Valley, past gated houses with security boxes to the home of Douglas Goldman, an heir to the Levi Strauss fortune and a software entrepreneur.
Across from the tennis court, hot tub, swimming pool and guesthouse, Mr. Goldman and his wife, Lisa, set up a cathedral tent decorated Hawaiian-style with bamboo trees and floral leis. Most of the 70 guests, including Google and AOL executives, paid $35,800 apiece. Mr. Obama teased the actor Don Cheadle about a basketball game they had played. But amid prosperous donors, he omitted the jab about Mr. Romney's "personal success."
After the speech at the Fox Theater and another fund-raiser, the president flew to Iowa the next day. While aides mainline coffee to stay awake, Mr. Obama sips tea or fruit juice. He spent the flight to Iowa editing speeches, scribbling in the margins. He wanted to directly attack Mr. Romney, who had visited the state the week before to complain about "a prairie fire of debt."
An aide suggested that he use his own farmland phrase and deride Mr. Romney's speech as "a cow pie of distortion." Mr. Obama inserted the phrase in a speech delivered at the Iowa State Fairgrounds, in a building sometimes used to demonstrate cow birthing.
Iowa pumped him up, and he and his senior adviser, David Plouffe, swapped nostalgic stories recalling the days when Mr. Obama's star was on the rise.
But the president was punchy after so many hours of traveling. As his motorcade rolled along, he called to check in with his wife, Michelle, and joked that if he headed west again, he could squeeze in even more events. "Yeah, we're just going to go to Japan and stay up and follow the sun." He has five more months to catch it to avoid the sun setting on his presidency.
This article originally appeared in The New York Times.