Democrats Barack Obama and Hillary Rodham Clinton sought common ground Thursday on basic Democratic policies on immigration, health care and tax relief in their first one-on-one debate, but grew testy at times in trying to distinguish themselves as the candidate best able to assume the presidency.

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Just days before the Super Tuesday contests, the two alternated addressing each other cordially with swipes, underscoring the high stakes of the upcoming contests. The debate came on the day when Obama's campaign reported raising a staggering $32 million in January, cash aplenty to advertise all through the Super Tuesday states, with its nearly two dozen contests from coast to coast, and beyond.

One of their most pointed exchanges came on the subject of whether illegal immigrants should be able to obtain driver's licenses. Obama supports doing so while Clinton initially supported it and now opposes it.

"Senator Clinton gave a number of different answers over the course of six weeks on this," Obama said, turning to Clinton. "Initially, you said you were for it, then you said you were against it." He said he was raising her apparent wavering to underscore that it is "a difficult political issue."

Clinton called the controversy "a diversion" from efforts to come up with comprehensive immigration reform. "I sponsored immigration reform before Barack came to the Senate," she said.

Obama argued for his candidacy, saying, "I respect Senator Clinton's record. I think it's a terrific record. But I also believe that the skills that I have are the ones that are needed right now to move the country forward, otherwise I wouldn't be running for president."

The two also reached out quickly to backers of former rival John Edwards, both praising his efforts in their opening statements.

Obama called Edwards "a voice for this party and this country for many years to come." Clinton saluted both Edwards and his wife, Elizabeth, as setting "their personal example of courage and leadership" in their advocacy for the poor.

Moments during the debate when the two candidates praised each other were mixed with pointed jabs.

Obama pressed his theme that he is the candidate of change. Clinton said "having the first woman president would be a huge change."

She also drew rounds of laughter in the Kodak Theatre -- home of the Academy Awards -- when asked about the Bush-Clinton family control of the White House for decades. "It did take a Clinton to clean after the first Bush and I think it might take another one to clean up after the second Bush," she said.

Befitting a Hollywood audience, among the stars in the crowd were Diane Keaton, Jason Alexander, Pierce Brosnan, Rob Reiner and Stevie Wonder.

Both candidates sought to ratchet back what had become increasingly personal attacks.

"I was friends with Hillary Clinton before we started this campaign. I will be friends with Hillary Clinton after this campaign is over," Obama said the day his campaign reported raising a staggering $32 million in January, cash aplenty to advertise all through the expensive Super Tuesday states, with its nearly two dozen contests, and beyond.

The two walked briskly together onto the stage, with Clinton walking in front of Obama and both waving to the audience. There was no attempt to shake hands, avoiding an uncomfortable moment. Obama faced questions earlier this week about whether he had snubbed Clinton in turning away from her at President Bush's State of the Union address on Monday night.

Both predicted that one of them would be the next president in a history-making inaugural, but then plunged into airing their differences on providing universal health care insurance, meeting with leaders of rogue nations and on Iraq policy.

Clinton also emphasized the importance for the next president to be ready to take over the job "on Day One."

"The next president will walk into the Oval Office and waiting there will be a stack of problems," Clinton said. She said these included "an economy not working for the vast majority of Americans."

Clinton said the Republicans are "more of the same" and, gesturing toward Obama, she said, "We will change our country."

The nation's weakening economy was a prime topic, and both candidates were pressed about the common Republican charge that they are tax-and-spend liberals.

Obama focused on Republican front-runner John McCain, praising his two votes against Bush's first-term tax cuts and questioning his support now for extending them. "Somewhere along the line, the Straight Talk Express lost some wheels," the Illinois senator said, referring to the name of McCain's campaign bus.

Both Obama and Clinton nodded in agreement as they compared Democratic economic solutions to those put forward by the GOP.