DES MOINES, Iowa -- As a long pre-primary campaign nears an end, the presidential contest has been turned upside down.
In both parties, the ground has shifted drastically under the leading contenders. Much of what strategists thought they knew is now in doubt, and the nominations are very much up for grabs.
At least as breathtaking has been the Republican upheaval. Rudolph W. Giuliani's wide lead in the national polls has slipped away. With the emergence of former Arkansas Gov. Mike Huckabee as a favorite of social conservatives, the most unpredictable Republican presidential contest in decades seems more uncertain than ever.
"Huckabee's rise is kind of unreal," said David Redlawsk, a University of Iowa political scientist. "I can't think of another example of somebody coming out of the back of the pack like that to challenge for the win."
Volatility, a defining characteristic of the 2008 race, is the result of a unique set of circumstances, including a compressed primary calendar and large candidate fields.
For the first time in memory, neither party will have a presumptive nominee or even a clear front-runner when the primaries and caucuses begin.
The absence of a logical successor and President Bush's unpopularity have left Republican voters searching for a new direction. Heading into the Jan. 3 Iowa caucuses, at least five candidates have a shot at winning the nomination.
Former Massachusetts Gov. Mitt Romney, who is outspending his Republican rivals in Iowa, has been overtaken by the lightly funded Huckabee, polls show. Among likely Democratic caucus-goers, Obama and Clinton are tied for first, with former North Carolina Sen. John Edwards a close third.
Edwards, who nearly won Iowa in 2004, got a lift from Newsweek, which is promoting him as "The Sleeper" on its latest cover.
Clinton also got a well-timed assist when The Des Moines Register endorsed her in yesterday's editions.
Recent published comments by a Clinton campaign official about Obama's past drug use had made the former first lady look desperate and risked a backlash from Iowa voters, Redlawsk said. The Clinton official resigned, and campaign aides insisted that there hadn't been a deliberate effort to inflict damage on her main rival.
It didn't help that Clinton herself, earlier this month, had described the new, more aggressive phase of her campaign as "the fun part," reinforcing some voters' perception that she's motivated more by political calculation than conviction.
David Axelrod, Obama's chief strategist, said the drug flap might be "doing us a favor." He noted that the aide who later quit Clinton's campaign had said that "this is what the Republicans would do" to Obama.
Now, "they're doing what the Republicans would do, and if we withstand that, we'll be stronger for it," the Obama adviser said.
A rival strategist said Obama seems to be fulfilling Democratic desires for someone who can take the country in a new direction.
"All you have to do is look at him on the television screen" to see that he represents "change, and I'm not talking about the fact that he's black," said Steve Murphy, a senior consultant to New Mexico Gov. Bill Richardson's presidential campaign. "If that's where the zeitgeist is headed, he's going to do very well."
Iowa Democrats said any of the three top contenders could win. They also said they wouldn't be surprised if Clinton finished third.
Asked if Iowa reflected the national mood among Democrats, Clinton's chief strategist implied that she would do better in the rest of the country, which has seen much less of the candidates.
In Iowa, "people's own experience with the candidates will play a bigger role, and in the other states the experience of the candidates will play a bigger role," said Mark Penn, underscoring a Clinton advantage.
Another factor compounding the '08 uncertainty: Iowa and New Hampshire, the initial voter tests, are just five days apart. That is closer than ever and could magnify the impact of winning Iowa.
"It may well be that Iowans control two states," said Rich Galen, an adviser to Republican candidate Fred Thompson, a former senator from Tennessee.
In New Hampshire, Romney continues to lead in recent polling. Campaign aides acknowledge that defeats in those states would likely doom his chances.
Arizona Sen. John McCain, who defeated George W. Bush in New Hampshire eight years ago, has slowly gained ground in the first primary state.
Largely written off after his candidacy nearly collapsed last spring, McCain has caught up with Giuliani for second place in recent statewide polling. Yesterday, The Boston Globe and Des Moines Register endorsed McCain, who earlier got the editorial backing of the Manchester Union Leader, New Hampshire's leading conservative voice.
Meanwhile, social and religious conservatives, a powerful force in Republican politics, appear to have finally found their favorite - Huckabee, an ordained Baptist minister with a solidly conservative record on social issues.
His success in Iowa, where evangelicals could cast up to half the caucus vote, is spreading to other states, despite scant organization or funding. But he's also getting more attention from Republican rivals, who hope to reverse his momentum by filling gaps in voters' knowledge of his record.
Last week, Huckabee became the target of one of the first negative television ads of the '08 campaign, a Romney spot highlighting Huckabee's support for college tuition breaks for illegal immigrants.
"They're attacking us on the mail, on the phone, on TV," said Chip Saltsman, Huckabee's national campaign manager. "If they can figure out a way to attack us with carrier pigeons, they probably will."
Even long-shot Texas Rep. Ron Paul, an unconventional presidential candidate who might have raised the most Republican money in the final three months of the year, is joining in. His campaign paid the travel expenses for Republican legislators from Arkansas who were in Iowa last week airing criticism of Huckabee on the state's top talk-radio show.
"The question on the ground in Iowa is about whether people will go to the caucuses believing that Mike Huckabee is a fiscal conservative, believing that Mike Huckabee is solid on immigration," said Gentry Collins, Romney's Iowa campaign manager. "Right now, he's getting the benefit of the doubt."
If Huckabee wins Iowa, it could help Giuliani, who will be lucky to finish third in the state and is hoping no front-runner emerges.
"This year is so difficult on so many levels," said Mike DuHaime, Giuliani's national campaign manager. Giuliani "always had a long-term strategy" that depended on winning Florida on Jan. 29 and doing well in the Feb. 5 primary states of California, New York, Illinois and New Jersey.
Many doubted that Giuliani's back-loaded strategy would work. Now all Republican bets are off. Advisers to several candidates have begun sketching plans for a race that extends beyond Feb. 5 and makes later primaries, including Maryland's on Feb. 12, unexpectedly important.