Behind the scenes, Clinton's campaign sent out a memo to reporters that tried to minimize the impact of the South Carolina contest.
"Regardless of today's outcome, the race quickly shifts to Florida, where hundreds of thousands of Democrats turn out to vote Tuesday," wrote Clinton Communications Director Howard Wolfson.
In a sign of how bad the blood is between the two campaigns, Obama's spokesman Bill Burton quickly sent a memo of his own.
"It should not be surprising given recent events that the Clinton campaign would in one breath say the election is about winning delegates and then tout their success in states that don't award any delegates in the next breath," Burton wrote.
That type of back-and-forth bickering between the Obama and Clinton campaigns allowed Edwards, who had moved up slightly in the polls in recent weeks, to argue he was the only "grown-up" in the race, running ads showing his rivals attacking one another at Monday night's debate.
"Vote for somebody who's actually focused on the problems that you're faced with, from jobs to health care to ending the war in Iraq, as opposed to two candidates who are spending all their time and energy tearing each other down. I'm about building South Carolina up, not about tearing people down, not about tearing politicians down," Edwards said Saturday, campaigning in Charleston.
The loss in his home state may have driven a stake through the former senator's presidential chances, but Edwards told ABC News' David Muir Friday he's going to continue to fight through Feb. 5.
Edwards advisers reportedly believe he could play kingmaker if his two rivals end up short on delegates.
On primary day the Clinton campaign launched a series of anti-Edwards robotic calls in South Carolina, reminding voters that Edwards once worked for a hedge fund that, the call stated, has been "profiting" from subprime lending and home foreclosures.
"You should also know that John Edwards made nearly a half a million dollars working for a Wall Street investment fund," the Clinton campaign call said, "A fund that's been profiting on foreclosing on the homes of families, including 100 homes right here in South Carolina."
In a race that has increasingly become a delegate war leading up to the Super-Duper Feb.5 primaries and caucuses, Obama won an estimated 25 delegates tonight, Clinton won an estimated 12 and John Edwards received 8 delegates.
Obama's campaign received another boost this weekend with the endorsement of Caroline Kennedy, the last surviving member of President John F. Kennedy's immediate family.
"Over the years, I've been deeply moved by the people who've told me they wished they could feel inspired and hopeful about America the way people did when my father was president," Caroline Kennedy writes in a New York Times op-ed Sunday. "This sense is even more profound today. That is why I am supporting a presidential candidate in the Democratic primaries, Barack Obama."
Arguing a "new wind" is at his back, Obama heads to Georgia and Alabama, states his campaign believes he can win, reports ABC News' Sunlen Miller.
The victory tonight gives Obama some much needed momentum before Tuesday's Florida primary and before voters in more than 20 states have their say Feb. 5.
ABC News' Gary Langer, Peyton Craighill, Dick Sheffield, Kate Snow, David Muir, David Wright, Eloise Harper, Sarah Amos, Sunlen Miller, Raelyn Johnson and Karen Travers contributed reporting.