WEST PALM BEACH, Fla. -- How do you decide whether to run against an incumbent president, especially one who is looking stronger in the polls?

A Reuters survey taken just days after the killing of Osama bin Laden showed President Obama leading all of the potential Republican candidates by a comfortable margin in hypothetical matchups.

The closest contenders were two former governors: Arkansas' Mike Huckabee, who trailed 51-39, and Massachusetts' Mitt Romney, who trailed 51-38.

Obama is riding a bump in the polls after approving the Navy SEAL operation that exterminated bin Laden, but that could diminish or disappear by November 2012. Voters said they were concerned about the economy and the 9 percent unemployment rate.

But if Republicans see Obama as particularly vulnerable, they aren't showing it, at least not yet.

The party's first presidential debate, held Saturday in Greenville, S.C., drew only one top contender, former Minnesota Gov. Tim Pawlenty. Former House Speaker Newt Gingrich, considered a long shot, became the first major GOP figure to formally enter the race on Wednesday.

Romney and Pawlenty have established exploratory committees, but neither they nor other prominent Republicans, including Huckabee, former Alaska Gov. Sarah Palin and Indiana Gov. Mitch Daniels, have declared their candidacies.

Party sources concede that fund raising is below 2008 standards.

To begin with, they are running against a sitting president. Nicol Rae, a Florida International University dean and an expert on the presidency, pointed out that incumbents have won more than 70 percent of the time.

''The incumbent has the ability to set the agenda and look presidential," said Rae, citing Obama's handling of the bin Laden raid.

Obama is a record-setting fund-raiser, so opposing him will be expensive. He is also commander in chief during military actions in Iraq, Afghanistan and Libya. That could insulate him from some GOP criticism, especially since he has largely followed the policies of former President George W. Bush on security matters.

But Kevin Wagner, a Florida Atlantic University political scientist, said he is still surprised that the GOP is not further along in selecting candidates.

''Democrats are harder to predict, while the GOP is usually a bit more orderly," he said. "Republicans do a familiar 'wait your turn' sort of thing. If it's anybody's turn, it's probably Romney's, but this is an atypical year. The inside operators are still looking for a candidate."

University of Miami political analyst George Gonzalez said Obama's policies of the past two years have influenced the GOP's thinking.

''Obama has moved toward the right," Gonzalez said. "That makes it harder to fashion a campaign against him."

Gonzalez cited Obama's extension of Bush-era tax cuts for all Americans, his troop surge in Afghanistan and his willingness to slash some social spending to decrease the deficit. Those policies angered members of his liberal base but may have earned support from independents.

If the economy continues to improve, running against the newly centrist president will not be easy, Gonzalez said. Republicans who want to challenge Obama might be forced further to the right to risky issues.

''The option is to run on the idea of cutting Medicaid and Medicare (to decrease the deficit) and addressing Social Security, and who wants to run on that?" Gonzalez said. "Obama's shift to the right has squeezed the Republican Party. Many of the potential candidates may choose to wait and run in 2016."

Gonzalez sees another advantage for Obama: With no apparent Democratic opposition, he won't have to win primaries. That might have forced him to curry favor with his liberal base, which might have turned off independents.

Most political analysts see Romney, 64, as the most likely GOP personality to declare next. According to published reports, he has much greater financial backing than other hopefuls.

''For him not to run this time would probably close out his opportunities to run ever," Gonzalez said.

Rae also believes Romney will declare soon. Romney, a successful entrepreneur, has the strongest resume on the nation's major issue: the economy.

''I think in the end it will come down to Romney and one other person out of that pack of contenders," Rae said.

Rae believes that too much is being made of the GOP's pace in establishing front-runners.

''The out-of-power party always looks a little lackluster at this stage," he said.

The power of incumbency also can be overstated, Rae said. He points to Ronald Reagan, who knocked off President Jimmy Carter in 1980, and Bill Clinton, who unseated George H.W. Bush in 1992. Carter and Bush, like Obama, were dealing with serious economic problems.

''An incumbent is not invulnerable," Rae said. "And they don't have to be seen as failed presidents. George H.W. Bush wasn't seen that way after his success in Kuwait, but he was caught having no serious answers for a serious recession. If the other party can present those answers, then the incumbent is vulnerable."

Rick Wilson, a Florida-based GOP consultant who worked for former New York Mayor Rudy Giuliani in 2008, sees no problem at the moment. Technology has changed how political opinion develops and candidates are chosen, he said.

''There is a longer decision-making process and it involves word spreading by Facebook, YouTube, Twitter," he said. "It takes time. I'm not convinced the field we have today is the one we're going to have next year."

For example, Giuliani was considered the front-runner in 2007 and wound up dropping out in January 2008, 10 months before the election.

''People said it was inevitable that Rudy would win," Wilson recalled. "Inevitability is a very funny thing these days."

Wilson learned his lesson: "I'm not supporting anyone at this time."

John Lantigua writes for The Palm Beach Post. E-mail: john(underscore)lantigua(at)pbpost.com.

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