Crowd greets Obama warmly, but without the euphoria of 2008

Madison, Wisconsin (CNN) -- "I'm fired up and ready to go!" President Obama yelled after casually walking on stage at the University of Wisconsin at Madison on Tuesday. The overwhelmingly student crowd cheered happily, but without the wild excitement they gave candidate Obama two years ago.

Obama looked visibly older and grayer than at his February 2008 campaign rally here, just a week before the presidential primary. He appeared slightly tired on his second day of travel, after arriving from a backyard discussion with voters in Albuquerque, New Mexico.

"Change is going to come! If we work for it! If we fight for it!" Obama cried defiantly.

White House aides billed this Democratic National Committee rally as an opportunity for the president to re-energize the base, to recapture the energy and magic that young voters brought to the Obama campaign. DNC officials estimated 15,000 would pack the mall across from the campus library -- a slightly smaller crowd than the 17,000 that filled UW's Kohl Center in 2008.

But University of Wisconsin Police Chief Sue Riseling reported the DNC exceeded its expectations, with 17,200 filling the outdoor space and 9,300 gathered in an overflow area a block away, for a total of 26,500.

Despite the numbers, the mood was markedly different from the euphoria of campaign days. The rally's headline entertainer, blues and folk singer Ben Harper, set a mellow mood with a quiet performance before the president took to the stage.

"The enthusiasm is definitely down," said 29-year-old Justin Ormont, a computer and nuclear engineering doctoral candidate. "We still have enthusiasm, but it's not at the same level. People can't live up to all your hopes and dreams. Obama made a lot of promises. Some he fulfilled, some he still has to work on."

In the speech, Obama said fulfilling his promises would take more time. "I understand that people are frustrated. I understand people are impatient with the pace of change. Of course they are. Look, I'm impatient, but I also know this: Now is not the time to lose heart. Now is not the time to give up. We do not quit."

Obama urged the crowd to vote in the midterm elections. "They're betting on your apathy. ... So Madison, you've got to prove them wrong," he implored. "Change happens from the bottom up. Change happens because of you," he cried, to applause. "Change happens because of you!"

For 20-year-old Olusheun Olupitan, a senior, the president's speech worked. "It was very informative. I'm more excited about voting in November. He reminded everyone what we should look forward to," Olupitan said.

Obama acknowledged the obvious. "I know it feels a long way from the hope and excitement of election day," he said. Growing more animated as his speech went on, the president exclaimed, "You elected me to do what was right. That was change you could believe in -- that I was going to do what was right, not what was expedient, not what was convenient."

Robert Pierce left the rally striking a more pragmatic tone. "It takes time. It's going to be a rough and hard way to go," he said. Pierce is not a student, but an older Obama supporter, a member of the group Growing Power, which promotes urban agriculture.

"A lot of people are disillusioned because they don't know what politics is all about. They need to dig deeper. Obama came out without any paper, he's speaking from the heart," Pierce said.