Des Moines, Iowa ? To grasp the carnival exuberance of the Democrats’ Jefferson-Jackson Day dinner here, consider Illinois Sen. Barack Obama’s triumphal march into the hall. Boogieing with his wife, Michelle, to the beat of the Isiserettes Drill and Drum Corps, Obama led a parade of hundreds of supporters chanting, “Fired up. Ready to go.”

With thousands of placard-waving, drum-beating party activists packing Veterans Memorial Auditorium, the “JJ” represents the traditional kickoff to the Iowa caucuses, just over seven weeks away.

In years past, the dinner – at least in retrospect – has signaled the emergence of the eventual caucus winner: John Kerry’s “don’t just send them a message … send them a president” in 2004, and Al Gore’s “I decided to stay and fight” jab at Bill Bradley in 2000.

Saturday night’s four-hour, six-candidate marathon did not present such an obvious separating-from-the-pack moment. But Obama’s impressive turnout and impassioned oratory offered the closing highlight of a long night that featured everything from literary recommendations (emcee Nancy Pelosi on Seamus Heaney’s “Beowulf” translation) to the auction of a homemade stuffed donkey signed by the candidates.

Hillary Clinton unveiled a new slogan, “Turn up the heat,” that slyly combines her toughness message with her gender appeal. “I know as the campaign goes on that it’s going to get a little hotter up here. But that’s fine with me,” she said, invoking Harry Truman. “I feel really comfortable in the kitchen.”

Clinton’s heat-raising was aimed at the other party – “We’re going to turn up the heat on Republicans and we’re going to turn America around” – but came with a brushback swipe at criticism by her rivals. “I’m not interested in attacking my opponents,” she said. “I’m interested in attacking the problems of America.” Easier to say, of course, from the comfortable perch of her party’s national front-runner.

Obama, undeterred, continued his stepped-up jabbing at Clinton even as he sold himself as the candidate best suited to bring to Washington a new, less polarizing way of doing business. “I don’t want to spend the next four years refighting the same fights that we had in the 1990s,” he said, and it’s safe to say everybody in the crowd remembered who was in the White House then. “The same old Washington textbook campaigns just won’t do it in this election … Not answering questions because we’re afraid our answers won’t be popular just won’t do it,” he said. “Triangulating and poll-driven positions because we’re worried about what Mitt or Rudy might say about us just won’t do it.” Take that, Mark Penn.

John Edwards’ message is the most radical, even angriest. His vision of change involves not holding hands with Republicans but throwing bombs at a corrupt system. “Washington is awash with corporate money, with lobbyists who pass it out, with politicians who ask for it,” he said. “It is time for us as a party to stand up with some backbone and some strength.”

The candidates’ themes dovetail with their theories of how to win the caucuses. Clinton is counting on turning out women, concentrating on those who have not previously attended caucuses, those over 55 who are among her strongest supporters and women in the kinds of jobs that require them to spend their days on their feet.

In this, Clinton could benefit from crucial support from the American Federation of State, County and Municipal Employees, which is sending scores of workers to the state, and Emily’s List, which had originally planned to help Clinton in states with primaries Feb. 5 but has switched gears to focus on getting Iowa women to caucus for her.

Obama is banking – not exclusively but at the margins – on younger voters, perhaps even high school students who are eligible to attend caucuses so long as they will be 18 at the time of the election, and who might motivate their parents to come along. He is also trying to lure independents and even Republicans who could switch parties on caucus night.

“The challenge for the next 53 days is whether he can close the deal with the Iowa voters,” says Obama strategist Steve Hildebrand. “He’s doing a better job of connecting with Iowa voters than he has before.”

Edwards, who finished second in Iowa four years ago and has invested enormous time and energy here only to find himself sinking to third place in recent polls, is counting on broad strength among rural and working-class voters. “We’re in third place,” Edwards campaign manager Joe Trippi offers in a cheery bid to lower expectations.

Still, he says, Edwards could end up benefiting at Clinton’s expense in the second-round voting. “She’s nobody’s second choice,” Trippi says. “We’re everybody’s second choice.”

The early caucus date, Jan. 3, presents another unknown. Will people barely recovered from New Year’s revelry be willing to drag themselves into the cold night? Will the students come back from winter break, especially if the Iowa Hawkeyes, who won Saturday, make it to a football bowl game? These are the strange wild cards on which the presidential race, and the Isiserettes’ hopes to march in an inaugural parade, could turn.