"For all of his youth, he's grayer and his wrinkles are deeper," said Bruce Buchanan, a presidential scholar at the University of Texas at Austin. "Given the rigors of that job, youth can be an advantage."
Obama was celebrating his birthday Wednesday night in his adopted hometown of Chicago with a campaign fund-raiser featuring jazz pianist Herbie Hancock and singer Jennifer Hudson. Ticket prices ranged from $50 to the legal maximum of $35,800 for the concert and dinner for more than 1,500 donors at the Aragon Entertainment Center.
The money will go to the Obama Victory Fund 2012, a joint Obama campaign and Democratic National Committee fund, a Democratic official who spoke on condition of anonymity said. Obama's campaign can accept $5,000 of each $35,800 contribution.
After the performances by Hudson and Hancock, Obama was attending a private dinner for 80 to 100 people at the same site. He was also conducting a video teleconference with supporters at more than 1,100 organizing meetings across the country.
Obama's reelection effort raised more than $86 million in the quarter that ended June 30, eclipsing the combined haul of the Republican field.
Republican National Committee Chairman Reince Priebus criticized Obama's fund-raising in a conference call Wednesday.
"The fund-raiser-in-chief is back in Chicago doing the thing that he's really good at and that's raising money to save his job," Priebus said. "This president, while he's in love with the sound of his own voice, he's not in love with following through on his promises."
On Thursday, his actual birthday, Obama is scheduled to attend meetings at the White House.
Just as Bill Clinton marked a move to a post-World War II generation of presidents, Obama and many of the Republicans competing for the White House represent another shift in age to leaders who were not yet adults during the height of the Vietnam War or the civil rights era.
Former Govs. Tim Pawlenty of Minnesota, who turned 50 in November, and Jon Huntsman of Utah, who is 51, are closest in age to the president. Former Massachusetts Gov. Mitt Romney is 64.
Among potential candidates who haven't announced, former Alaska Gov. Sarah Palin would, at 47, be the youngest if she joined the campaign.
Clinton, who entered the White House a year younger than Obama, was the last president to turn 50 while in office.