DES MOINES, Iowa - Just before the stroke of midnight today, Sen. Barack Obama will gather his Iowa staff members and volunteers from across the state, so they can all celebrate the new year together.

On a conference call.

So goes this New Year's Eve in Iowa, at least among the thousands of campaign-staff members, volunteers, contributors, journalists and other hangers-on hunkering down in anticipation of the caucus here on Thursday. With many polls showing both the Democratic and Republican races as true toss-ups, 2008 arrives amid grueling last-minute campaign sprints. And instead of promises of fresh starts, the new year for some could mean the potential end of their candidacies.

The result is likely to be the most bizarre New Year's Eve many here can remember. There is a veneer of festivity - not every campaign's approach is as ascetic as Obama's - but it is a thin and transparent one. For many, the holiday feels cruelly ill-timed: How can they gaily celebrate the start of 2008 when in fact they are consumed with anxiety about what happens two days later?

"No one knows what 2008 will bring in terms of the political process," said Carolyn Weyforth, deputy communications director for former Gov. Mitt Romney of Massachusetts, whose once-comfortable lead in the Iowa polls has been erased by former Gov. Mike Huckabee of Arkansas. "The rest of the country is worried about whether they are going to lose weight this year, and our immediate thought is what's going to happen January 3 and January 8," she said, referring to the dates of the Iowa caucuses and the New Hampshire primary.

While the campaigns took a mutually agreed-upon timeout for Christmas, New Year's Eve could play host to crucial developments in the race. Candidates will be campaigning up to and even throughout the evening, meaning that a major gaffe or verbal fusillades among contenders are possibilities. And the Des Moines Register is planning to release its final pre-caucus poll in tomorrow's issue, which will hit the paper's Web site in today's final hours.

The expression around Huckabee's downtown campaign headquarters, said Daniel Hay, a college student and volunteer who expects to work late tonight, is "Happy New Year plus two days," meaning that the holiday is delayed until after what the Huckabee camp hopes will be a first-place caucus finish.

There will be parties, of course: The campaigns of Sen. Hillary Rodham Clinton, Gov. Bill Richardson of New Mexico, Huckabee and Romney are holding events in Des Moines; the campaign of former Sen. John Edwards is having one at its office in Mason City; and Sen. Christopher J. Dodd is holding one in Dubuque.

For the candidates with the lowest standing in the polls, the parties will probably have an elegiac air. Dodd, Democrat of Connecticut, has pinned his primary hopes on this state - he even moved here - and polls suggest he has virtually no chance of winning on Thursday. So his party sounds much like a goodbye-and-thank-you affair. "We're going to be celebrating all the work the senator and the volunteers have put in over the last year," said Colleen Flanagan, his press secretary.