In the Republican ranks, Mr. McCain, 71, is a curious bookend to Mr. Obama. He is the oldest candidate in either party besides Ron Paul, another Republican, who is 72. Yet he draws hundreds of young people at some events.
Mr. McCain drew many hundreds when he spoke at Dartmouth, a number exceeded only by the 2,000 students who showed up for Mr. Obama.
“He is seen as Washington but not in it,” said Ronald G. Shaiko, an associate director of the Nelson A. Rockefeller Center at Dartmouth who works with focus groups. “They think he’ll upset the apple cart.”
Mr. McCain admits to admiring Mr. Obama’s appeal as a “wonderful thing” and has taken to borrowing a line or three. He has been channeling Mr. Obama, calling on Americans to “serve a cause greater than their self-interest,” a theme from his campaign in 2000.
At forums, he may hand the microphone to a young man with ONE, a group dedicated to eradicating what it calls “stupid poverty” and disease. The group has more than 17,000 members in New Hampshire.
At Dartmouth, Emily Goodell, 18, sat astride a strange fence, contemplating a vote for Mr. McCain or Mr. Obama.
“It is kind of a strange thing since they have different views on many of the issues,” Ms. Goodell said. “They come across as genuine. I trust them.”
Nearly as striking is the absence of young people on the trail traveled by Mitt Romney and Rudolph W. Giuliani. Mr. Romney visited Dartmouth, but the earth did not shake.
“He went straight to the medical school,” Professor Shaiko said. “He wanted to talk to adults. He has no presence here.”
Still, the youth vote has an uncertain mojo. For the moment, Mr. Obama is like catnip for many people younger than 30. Less certain is if his “it moment” will be sustained.
The results of the Rockefeller Center focus group before the Democratic debate in September at Dartmouth may be instructive. Mr. Obama’s stock dropped after he stood shoulder to shoulder with more experienced rivals.
“His talking about his work in the state legislature while another candidate is talking about negotiating with the North Koreans was a turnoff,” Professor Shaiko said. “They found him coming up short on experience.”
It has been an interesting turnaround for Senator Obama in those three months, and it has been equally interesting to see this aura emerge around him and Senator McCain. It does not seem to have much to do with the two parties, either. The longest line at the polling place was still the one to change affiliations back to undeclared.