SAN DIEGO - The volatile Republican presidential contest in California has turned upside down in the past month and now stands as a close race between Sen. John McCain of Arizona and former Massachusetts Gov. Mitt Romney, according to a new Field Poll.
That race became even tighter Tuesday when former Sen. Fred Thompson of Tennessee dropped out.
The poll shows McCain leading with 23 percent to Romney's 21 percent as the Feb. 5 primary approaches.
A month ago, the Field Poll showed former New York Mayor Rudy Giuliani comfortably ahead of the pack and former Arkansas Gov. Mike Huckabee in second place.
Now, Giuliani has slipped to third place with 13 percent and Huckabee fourth with 12 percent. Rep. Ron Paul of Texas placed fifth with 7 percent.
"I've never seen such an unsettled field two weeks before an election, at least in a presidential primary," Field Poll director Mark DiCamillo said.
The poll shows a sharp ideological split among Republicans considered likely to vote in the primary.
"It's a tug-of-war between the moderate wing and the strong conservative wing, with Romney the favorite of the conservatives and McCain the favorite of the moderates," DiCamillo said.
Republicans who describe themselves as "strongly conservative" support Romney over McCain, 26 percent to 16 percent.
Republicans who describe themselves as "moderately conservative," "moderate" or "liberal" favor McCain over Romney, 27 percent to 9 percent.
McCain has run well among nonpartisans in states such as New Hampshire that permit them to vote in either primary. In California, Democrats allow voters who are registered "decline to state" to vote in their presidential primary, but Republicans do not.
Thompson's departure from the race boosted Romney into a statistical tie with McCain.
With Thompson in the race, the poll showed McCain leading Romney 22 percent to 18 percent, Giuliani and Huckabee tied at 11 percent, Thompson at 9 percent and Paul at 7 percent. With Thompson out of the race, the poll showed Romney cutting McCain's lead in half.
Given how the polls in California have shifted in response to the results in other states, DiCamillo said the numbers could be shaken up again before Feb. 5, depending upon the outcome of Tuesday's primary in Florida.
Giuliani, once the national front-runner, is seeking to revive his struggling candidacy with a win in Florida.
Because Giuliani and McCain are competing for the votes of moderate Republicans, DiCamillo said, "If he stays weak, that helps McCain." Likewise, he added, Romney would probably benefit if Huckabee fades.
Republicans surveyed had highly positive opinions about McCain and Romney, less so about Giuliani and Huckabee.
Among Republican voters, 68 percent said they had a favorble view of McCain to 22 percent unfavorable. About Romney, the percentages were 59-23; Giuliani, 54-31; and Huckabee, 51-26.
The Field Poll also asked Republicans to evaluate the candidates on six personal and political characteristics.
Republicans rated McCain highest on experience, with 36 percent to 21 percent for Romney and Giuliani, 4 percent for Huckabee.
Thirty-two percent said McCain would be the strongest general election candidate to 20 percent for Romney, 18 percent for Giuliani and 7 percent for Huckabee.
As for who "will be able to unite the U.S.," it was McCain at 29 percent, Romney and Giuliani each at 20 percent and Huckabee at 5 percent.
Romney scored best on which candidate "best represents change," 23 percent to 18 percent for McCain, 16 percent for Giuliani and 14 percent for Huckabee.
On which candidate "shares your values," Romney came in at 27 percent, McCain at 24 percent, Huckabee at 15 percent and Giuliani at 12 percent.
Romney also held a substantial lead in regard to which candidate "best represents what the Republican Party stands for" with 32 percent, compared with 20 percent for McCain, 13 percent for Huckabee and 10 percent for Giuliani.
That may prove to be a significant statistic, DiCamillo said.
"I think that attribute is an important one in deciding who the Republicans nominate because they want one of them," the pollster said. "They want a Republican who represents the party, and that's why it's a closed primary."
Republican voters were also asked which issues are the most important for them in deciding who would get their vote.
Illegal immigration ranked at the top with 40 percent mentioning it. Thirty-seven percent said the threat of terrorism, 33 percent the war in Iraq and jobs and the economy, 25 percent foreign policy, 24 percent taxes and 18 percent health care.
When the Field Poll posed the same question to likely voters in the Democratic primary, the list of issues was almost reversed: health care, 43 percent; the war in Iraq and jobs and the economy, 42 percent; foreign policy, 30 percent; illegal immigration, 26 percent; taxes, 19 percent; and the terrorism threat, 17 percent.
The Field Poll is based on telephone interviews conducted with 377 voters considered likely to vote in the Feb. 5 Republican primary election. The poll was conducted between Jan. 14 and Sunday and has a margin of error of 5.2 percentage points.