The L.A. Times/CNN/Politico poll, conducted by Opinion Research Corp., showed that the race remains extremely fluid, even as voters in the state are casting mail-in ballots. Six in 10 Republican primary voters said they might change candidates in the next three weeks. Among Democrats, four in 10 said they could still change their minds.
As things stand now, Clinton leads Obama 47% to 31% among voters judged likely to cast ballots in California. A third candidate, former North Carolina Sen. John Edwards, was a distant third with 10%.
The poll provides the first public glimpse of the race in the nation's largest state since the initial round of contests in Iowa and New Hampshire began to winnow the field.
As she did in New Hampshire, where she eked out a win over Obama last week, Clinton held on to a sturdy margin among registered Democrats. But the New York senator also opened a strong lead over her colleague from Illinois among independent voters. Registered voters who have declined to state a party will be able to cast ballots in California's Democratic primary but not in the GOP contest.
Those planning to vote in the Democratic primary here, as in Iowa and New Hampshire, embraced the notion of "change" as more crucial than "experience" in deciding which candidate to support. Obama led among voters who said change was their top priority.
Clinton, who has touted her experience and equated a vote for Obama with risk, dominated among those who hewed to experience but remained the choice of almost a third of voters who said change was imperative. By wide margins, Democratic voters also said Clinton would be the candidate best equipped to battle the Republicans in the fall.
"She has experience -- I always think that's really important," Ruth Torres, a retired school psychologist from Sierra Madre, said in a follow-up interview with The Times.
"I know a lot of people who are for change," she said, including Obama voters in her own family. "Whoever is elected, we will have change."
The Republican race is far more uncertain. Among likely voters, Arizona Sen. McCain was ahead with 20%. Mitt Romney was at 16%, Rudolph W. Giuliani at 14% and Mike Huckabee at 13%. All four were within the poll's margin of sampling error. Rep. Ron Paul of Texas had 8%, and former U.S. Sen. Fred Thompson was at 6%. Rep. Duncan Hunter of Alpine did not register on the poll.
Overall, Republicans judged McCain to be the GOP candidate best positioned to defeat the eventual Democratic nominee, and -- by a broad margin -- listed him as the candidate most possessing honesty and integrity.
The survey, supervised by Times Poll Director Susan Pinkus, interviewed 1,054 registered voters between Friday and Sunday, including 384 likely to vote in the Democratic primary and 255 Republican likely voters. The margin of sampling error was 5 points among those likely to vote in the Democratic primary and 6 points among Republican likely voters.
The survey results -- particularly regarding the fog of uncertainty enveloping many voters -- captured a presidential race in a high state of flux. Among Democrats, the race has seesawed between Obama, winner of the Iowa caucus, and Clinton. Both have made repeat visits to California and will be meeting voters here this week.
The GOP race has been even more of a roller coaster, with Huckabee winning the caucuses and McCain surging back to win New Hampshire -- both at the expense of Romney, the former Massachusetts governor who spent millions in pursuit of early wins. Romney and McCain are locked in battle in Michigan, which votes today. McCain, Huckabee and Thompson are vying in South Carolina, which votes Saturday.
Former New York Mayor Giuliani, long the national front-runner, has slumped recently. He has pinned his hopes on the chance that the Florida primary, on Jan. 29, would vault him into a strong position in the score of states voting Feb. 5.
Adding to the complications for the campaigns in California, voters have been able to cast mail-in ballots since Jan. 7. Voters may still request absentee ballots until Jan. 29. The last day to register to vote is Jan. 22.
Campaign and election officials expect at least half of the state's voters to cast ballots by mail, and in the poll, the distinction between the two voter pools was evident in the Republican race. Traditional precinct voters had the race a dead heat between McCain, Giuliani and Romney. But McCain held a strong lead among mail-in balloters.
Men were more strongly in McCain's corner, while women voters split between McCain and former Arkansas Gov. Huckabee, with Romney close behind.
Orvis Adams, a retired aerospace program manager and former Navy crewman from Los Alamitos, said he backed McCain in part because of his heroism as a Vietnam War prisoner of war.