THE NOTE: Caucus Day

Jan. 3, 2008 -- DES MOINES, Iowa --

To the longest, most intense presidential campaign in American history, we introduce a new element on Thursday: voters.

Welcome -- you've missed so much, but (as this first contest is bound to show) really nothing at all. The party couldn't start without you.

It will be bone-cold, blustery, yet generally clear across the Hawkeye State when what's likely to be a record number of Democrats -- and a decidedly low number of Republicans -- drop by one of some 3,562 sites (that's 1,781 precincts times two) to engage in the peculiar exercise of American democracy known as the Iowa caucuses.

When it's done, a measure of clarity will descend upon this unwieldy presidential race. Frontrunners will be anointed, momentum will be generated -- and Iowans will almost certainly consign some also-rans to footnotes on Wikipedia pages.

But before we get inside the warmth of the caucus rooms -- starting at 7 pm Iowa time, 8 pm ET -- the frantic, frigid dash continues. All three front-running Democrats ended the Iowa campaign with *blocks of TV time during Wednesday evening's Iowa newscasts, and you can't turn on a television without seeing some candidate on some talk show -- or at least, if you're in Iowa, and ad or 12.

Even late-night television got its dose of Campaign '08, with Sen. Hillary Rodham Clinton, D-N.Y., taping a line to mark David Letterman's return to the air, and former governor Mike Huckabee, R-Ark., grabbing Jay Leno's couch (and making one last gaffe by not realizing he was crossing a picket line to do so).

"Oh well -- all good things must come to an end," Clinton told Dave, talking about the writers' strike -- but it could just as easily apply to Iowa.

Among the Democrats, the campaign ends essentially where it started roughly a year ago -- no histrionics, just candidates pushing forward with their messages. Clinton "asked voters at rallies and in a two-minute television commercial broadcast statewide, 'Who is ready to be president?' " The New York Times' Jeff Zeleny writes.

"Senator Barack Obama, Democrat of Illinois, implored supporters to believe in his candidacy, asking, 'Who can take us in a fundamentally new direction?' John Edwards of North Carolina pledged to represent struggling Americans, saying, 'Who's going to fight for you?' "

Obama closed out his final night campaigning in Iowa with a praise for what he called "the best grassroots organization that Iowa has ever seen," ABC's Sunlen Miller reports. "All [the] rallies, all the excitement, all the fun, all that's behind us, and what matters is do we show up, do we stand up, do we reach for what's possible tomorrow?" Obama said.

On the Republican side, the battle for first is between longtime frontrunner (and big-time spender) former governor Mitt Romney, R-Mass., and Huckabee, who burst onto the scene only in the final month-plus of the campaign. And they're sparring until the end.

"People are looking for a presidential candidate who reminds them more of the guy they work with, rather than the guy that laid them off," Huckabee told Leno, after jamming with "The Tonight Show" band in a scene reminiscent of Bill Clinton on Arsenio.

There's another big GOP battle -- for third place. A strong showing by Sen. John McCain, R-Ariz., would be a huge boost for his candidacy, particularly with the New Hampshire primary -- where he's in a virtual first-place tie -- just five days away. He'll be a secondary winner -- and the big story going into the weekend -- if he takes a decisive third.

Former senator Fred Thompson, R-Tenn., has said he needs to come in second place -- an increasingly difficult task for the late-starting (and slow-moving) candidate. Thompson could top the Iowa casualty list, with Sen. Chris Dodd, D-Conn., generally viewed as the most likely Democrat to exit the race if he has a poor showing on Thursday.

"Without a solid third-place finish, there's no point in going on," a Thompson adviser tells Politico's Jonathan Martin and Mike Allen.

They write: "Thompson's departure could shake up the race more than his continued presence. Friends and advisers said they have long considered it likely that if the lobbyist-actor is forced from the race he would endorse John McCain his former Senate colleague who lately has been staging a political revival in New Hampshire."

There are only two factors left that campaigns can hope to control (and they will learn to their frustration on Thursday night that they really don't control either one): expectations and turnout.

From the vantage point of the Democrats' gurus, the campaign comes down to a clash between Joe Trippi's angry passion (the Edwards campaign), Mark Penn's poll-tested numbers (Clinton), and David Axelrod's soaring vision (Obama).

Obama's campaign -- with his hope-ing mad rhetoric and his appeal to independents and Republicans -- represents the biggest challenge to the traditional assumptions surrounding the caucuses and the nominating process more broadly.

"America will finally have an answer to the question: Is Obama another Howard Dean, or can he win the nomination?" Dana Milbank writes in The Washington Post. "Like Dean, he has challenged the Democratic establishment with a coalition of students and political independents. His candidacy, like Dean's, will collapse if they don't show up."

"It is, in other words, a battle between the passion and the machine, between Hillary Clinton's establishment support and the superior enthusiasm of Obama's supporters," Milbank continues. "The Republican contest here is almost identical: a fight between an establishment candidate, Mitt Romney, and an insurgent favored by evangelicals, Mike Huckabee."

A big turnout would seem to favor Obama, since he's counting on the largest number of first-time caucus-goers -- including students and non-Democrats, per Sasha Issenberg of The Boston Globe.

"A victory for Obama would offer proof not only of his electoral viability, but demonstrate a constituency for his calls of national unity and validate his optimism that the partisan environment of American politics can be successfully challenged," Issenberg writes.

Like the other candidates, Obama is seeking to convey optimism without cockiness; he wants to find a way to declare success even if caucus night ends with a celebration in somebody else's ballroom.