Even as his turn on the global stage hit an emotional peak Thursday with a speech before a cheering crowd of more than 200,000 in Germany, Barack Obama faced new evidence of stubborn election challenges back home.
Fresh polls show that he has been unable to convert weeks of extensive media coverage into a widened lead. And some prominent Democrats whose support could boost his campaign are still not enthusiastic about his candidacy.
Several new surveys show that Obama is in a tight race or even losing ground to Republican John McCain, both nationally and in two important swing states, Colorado and Minnesota. One new poll offered a possible explanation for his troubles: A minority of voters see Obama as a familiar figure with whom they can identify.
Republicans are moving to exploit this vulnerability, trying to encourage unease among voters by building the impression that Obama's overseas trip and other actions show he has a sense of entitlement that suggests he believes the White House is already his.
In Ohio on Thursday, McCain hit that theme: "I'd love to give a speech in Germany . . . but I'd much prefer to do it as president of the United States, rather than as a candidate for the office of presidency."
Obama also faces discontent from some of Hillary Rodham Clinton's most ardent supporters, who are put off by what they describe as a campaign marked by hubris and a style dedicated to televised extravaganzas.
Susie Tompkins Buell, a major Clinton fundraiser, said: "The Clinton supporters that I know are bothered by these rock-star events. These spectacles are more about the candidate than they are about the party and the issues that we care about."
Obama is to return home Saturday after a nine-day trip that has produced some of the most memorable images of the campaign. Speaking in Berlin before a sea of young faces, the presumed Democratic nominee echoed a famous line from President Reagan, who, at Brandenburg Gate, implored Soviet counterpart Mikhail S. Gorbachev to "tear down this wall."
"The walls between races and tribes, natives and immigrants, Christian and Muslim and Jew cannot stand. These now are the walls we must tear down," Obama told the warmly enthusiastic crowd in Tiergarten park. He spoke from a stage constructed near the Victory Column, a soaring monument to Prussian military triumphs.
Powerful as the image was, back home some voters wondered whether the trip was necessary. Both Obama and McCain had been invited Thursday to a cancer forum organized by cyclist Lance Armstrong's foundation at Ohio State University.
McCain showed; Obama did not. Some in the crowd took notice.
Ann Marie Jones, a stay-at-home mother whose 10-year-old son was diagnosed with cancer in September, said she had leaned toward Obama "until he didn't show up tonight."
"I feel like I understand what he's doing over there, but I think he needed to be here tonight for this," she said.
Jones, a 40-year-old Republican from Aledo, Texas, said she was troubled by the duration and scale of Obama's overseas trip. "I think we have a lot of things going on with our children -- many different things going on here in the United States that need our attention."
Many voters still seem to be puzzling over who Obama is, even after a race that has lasted a year and a half. By 58% to 47%, voters identify more with the values and background of McCain, the presumptive Republican nominee, than with Obama, according to a newly released Wall Street Journal/NBC News poll.
Obama may also be slipping in some key states. He lost a narrow lead in Colorado, falling 5 percentage points in the past month, and now trails McCain 46% to 44%, a new Quinnipiac University poll found. In Minnesota, Obama fell 8 percentage points, though he still leads McCain 46% to 44%, the survey found. The polling spanned the five days before Obama went abroad and the first four days of his trip.
At a time when nearly three-quarters of Americans believe the nation is on the wrong track, the political climate would suggest that McCain, whose party controls the White House, might lag by large margins. Yet a national Fox News poll released Thursday showed that Obama's 4-point lead over McCain in June had shrunk to a single point. The new Journal/NBC poll showed Obama leading by 6 points, unchanged from the month before.
The race remains close even though McCain has stumbled at times and has been largely eclipsed this week by Obama's high-profile trip to Europe and the Middle East, including Iraq and Afghanistan.
On Thursday, television images showed Obama addressing the throng in Berlin, his speech carried live on cable news networks. McCain, meanwhile, spoke to reporters outside an Ohio fudge shop, where his comments were nearly drowned out by wind chimes.
But Obama is struggling with a different set of obstacles; he has yet to lock in some of Clinton's most devoted supporters and active fundraisers.
In interviews, Clinton supporters said they saw in Obama a presumption that had made it hard to give him their allegiance. Some said they were put off by his decision to accept the Democratic nomination at a football stadium that can hold more than 76,000; his use of a knockoff of the presidential seal at a campaign event; and his early interest in giving his Berlin speech at the famous Brandenburg Gate, where Reagan spoke in 1987.
The Republican National Committee has been pumping out regular e-mails titled "Audacity Watch," a compilation of instances in which, in its view, Obama has appeared to act as if he were president. In an e-mail sent Thursday, the RNC mentioned a news report that he had already instructed aides to begin planning for a transition to the presidency.
Amy Siskind of Westchester, N.Y., is a Clinton supporter who said she wouldn't vote for Obama. Siskind said she was especially offended when Obama hired Clinton's former campaign manager, Patti Solis Doyle, to work with his vice presidential nominee. Given that Solis Doyle was demoted by Clinton, the appointment was perceived by Clinton loyalists as a slight.
"Most folks feel that the battle is over and he's the winner, but he's really acted like a sore winner," Siskind said. "If Hillary had been the nominee, you would have seen a much more deferential approach to Obama supporters."
Lynn Forester de Rothschild, a Clinton fundraiser who lives in New York City, said, "What I think is very important is that he has a problem with his image. He is an aloof candidate. He does not connect with people. He has words, but no ordinary person thinks that he is there for them, and women feel that intensely."
Time remains for Obama to unify the party and find ways to win over skeptical voters. His campaign released ads last month that emphasize the parts of Obama's life story that a typical voter might find appealing. Obama, for example, was raised by a single mother and grandparents who lacked substantial means.
The campaign hopes that the images in those ads will boost his standing in the polls.
"As we tell Sen. Obama's story -- being raised by a single mother, pulling himself up, working his way through school -- people will become more familiar with him," said Hari Sevugan, an Obama campaign spokesman.
Seeing an opportunity, McCain's supporters have sought to drive home perceptions that Obama doesn't connect with average voters.
"The fact that Obama is out of touch with voters . . . is certainly something we'll continue to reiterate," said Alex Conant, a spokesman for the Republican National Committee. "To the extent that he's acting as if he's already president when the election is over 100 days away and everyone expects it will be a very close race raises questions about how in touch he is."
Times staff writer Maeve Reston in Columbus, Ohio, contributed to this report.