Sen. Hillary Rodham Clinton maintains a solid lead in her party's presidential race among Democratic voters nationwide, despite a surge in support since late last year for Sen. Barack Obama, a Los Angeles Times/Bloomberg poll has found.
The Republican presidential contest finds voters divided among three candidates -- Sen. John McCain of Arizona, former Arkansas Gov. Mike Huckabee and former Massachusetts Gov. Mitt Romney. Former New York Mayor Rudolph W. Giuliani has sagged from first place to fourth, according to the survey.
Clinton was preferred by 42% of the likely Democratic voters polled, and Obama by 33% -- a significant increase for the senator from Illinois since a similar poll in early December, when he was the choice of 21%. Support for the senator from New York remained virtually unchanged over that period.
The overall preference figures mask a pronounced racial divide among Democratic voters: About two-thirds of black respondents said they would vote for Obama, whereas only about a fourth of white respondents said he was their choice.
The poll also found that an increasing number of Democratic voters -- about two-thirds -- said they were certain whom they would vote for, making major swings in preference less likely as the primary season heads into the states with the most delegates at stake.
"Now that Democrats have winnowed down their race to two leading candidates, they are moving toward the candidates they will probably vote for," said Susan Pinkus, the poll's director. "Obama has gained some support, but Clinton has not lost any. The question now is: Where do the remaining voters go?"
Former Sen. John Edwards of North Carolina drew the support of 11% of Democratic respondents. When asked for whom they would vote if their first choice dropped out, slightly more Edwards voters leaned toward Clinton than toward Obama, the poll found.
In the GOP contest, the survey found that 22% of likely Republican voters preferred McCain, 18% backed Huckabee and about the same proportion -- 17% -- chose Romney. Because of the poll's margin of error, the differences among these three candidates are not statistically meaningful.
Giuliani was supported by 12% of likely GOP voters, down dramatically from 32% in an October poll and 23% in the December survey. He decided not to compete actively in the first few contests in the Republican race, instead staking his candidacy on a strong showing in Florida's primary this coming Tuesday.
Former Sen. Fred Thompson of Tennessee, who ended his candidacy Tuesday, drew 10%, and Rep. Ron Paul of Texas, whose fundraising from a committed core of supporters has outpaced that of some better-known candidates, drew 6%.
The Republican electorate remains notably volatile. Barely more than half of Republican voters surveyed were certain that they would stick with their first choice; 41%, including about half of Romney's supporters, said they might change their minds.
"The Republican race is still wide open," Pinkus said. "Republican voters are still trying to figure out who their candidate is . . . and most of them aren't very satisfied with their choices."
In a reflection of the GOP's uncertain state, Republican voters who described themselves as conservatives were far from united around a single candidate. Instead, about a fifth chose McCain, a fifth chose Romney, and the rest were divided among other candidates.
In a sign of potential trouble for Huckabee, only 25% of Republican voters who described themselves as evangelical Christians named him as their first choice, despite his emphasis on traditional social values. Among evangelicals, McCain was the second-most-popular at 19%, despite his past friction with leaders of the religious right.
In hypothetical general-election matchups, both Clinton and Obama run well ahead of Romney, Huckabee or Giuliani. McCain, by contrast, is the one Republican within striking distance of defeating either of those Democrats in the general election.
"McCain is the only Republican at this point who would give Clinton or Obama a run for their money," Pinkus said. When the Arizona senator is matched against either Clinton or Obama, Pinkus said, they virtually split the independent vote.
Most Clinton voters said they would like to see their candidate choose Obama as her running mate. Most Obama voters said they would like to see him choose Clinton for the second spot.
Among both Democratic and Republican voters, the sagging economy has quickly become an overriding priority, the poll found. Among Democratic voters, it was named as the most important issue almost as often as the war in Iraq; among GOP voters, no other issue came close.
That newfound concern could, over time, benefit the two candidates whom voters identified as the best-equipped to deal with economic problems: Clinton and Romney.
The poll suggests that Clinton has solidified her hold on several core constituencies in her party: Voters older than 65, Catholics and married women all support her candidacy at a level of 50% or higher. Obama, by contrast, draws strong support from African Americans and more-affluent voters.
The survey, conducted under Pinkus' supervision, was based on interviews Friday through Tuesday of 1,312 registered voters, including 532 who expect to support a Democrat and 337 who expect to support a Republican.
The margin of error was plus or minus 4 percentage points for the Democratic sample and plus or minus 5 points for the GOP group.
For questions asked of all registered voters, the margin of error was plus or minus 3 percentage points.