HANOVER – More than 5,000 people flooded a Dartmouth College courtyard yesterday for a political rock-star session with Democratic Presidential candidate Sen. Barack Obama.

After an a cappella performance by the Dartmouth Airs and an introduction by Congressman Paul Hodes, Obama jumped onto a platform above the sea of enthusiastic supporters, an American flag fluttering behind him, as the refrain, "Oh, freedom, freedom ...," from Aretha Franklin's "Think," provided the soulful soundtrack.

These days Obama is measuring his success not just in poll numbers, money raised or endorsements -- but by the size of the crowd.

"We have been attracting these enormous crowds all across the country," he said over the weekend during a town hall-style meeting. "There is a sense of urgency, and I think it's why people are showing up in record numbers, not just to my events, but to political events all over the country."

People are hungry for change, Obama said.

"People recognize that the day this President steps down from office, the entire world will breath a sigh of relief," he said.

The all-ages crowd in Hanover yesterday exploded with applause when Obama called for an end to the war in Iraq and better services for veterans.

The former civil rights lawyer and professor of constitutional law explained that watching civil rights activists in Chicago when he was young spurred his involvement in community organizing and politics.

"People want to be involved. They just have to be asked," said Obama, standing on a lawn between two college buildings, a packed crowd before him.

Turnout in the more sparsely populated North County typically pales when compared to venues farther south. But Obama's appeal -- and aggressive organizing machine -- are defying expectations up there, too.

"I've been to rock concerts. I've seen crowds this size. But for a candidate? No," said Jay Smith, a Madison resident who stood outside for an hour to get into a Conway middle school gym Sunday.

The Obama campaign said Smith was one of 1,200 in the standing room-only venue. Later that day, almost 300 people turned out for a cold, overcast, evening ice cream social in Berlin. And another 250 people packed into a stuffy community center in Littleton yesterday.

For a hopeful whose nomination is hardly a certainty, Obama is drawing bigger crowds than any of his 2008 rivals. His Springfield, Ill., campaign kickoff brought an estimated 15,000 people to a cold, outdoor event. He says 9,000 people showed up in Los Angeles. Another 20,000 showed up in Atlanta and Austin.

"It's what you call a high-class problem," Obama joked with reporters yesterday. It's also a smart campaign strategy, experts said.

"There are very few hard numbers at this stage of the games. There's dollars and there's crowds. There are polling numbers, but they're notoriously fluid. The crowds are something campaigns try to hang something on," said Dante Scala, an associate professor of political science at Saint Anselm College. "It tends to reinforce the notion he's a top-tier candidate. When (Sen. Chris) Dodd gets 100 at a house party, it all looks small in comparison."

The Associated Press contributed to this report.