Reaching and winning over those undecided voters -- and then getting them to show up on caucus night -- is the main challenge for the campaigns in the few remaining days. The campaigns are pulling out all the stops to do that, from appearances with symbolic surrogates (Ted Strickland, the governor of the perennial battleground of Ohio campaigned with Clinton over the weekend) and celebrities ("Superman Returns" star -- and Iowa native -- Brandon Routh introduced Obama last night in Indianola) to massive door-knocking and phone-calling campaigns.

Given the craziness in the final days, it's sometimes hard to see the forest for the trees. Here's our attempt to do just that.

DEMOCRATS

The race -- as it has been for many months -- is a three-way affair between Clinton, Obama and Edwards.

What's clear from being on the ground here in Iowa is that Edwards's surge over the past week is real. The former North Carolina senator's closing message is extremely sharp, appealing directly to those who feel most disenchanted with the state of the country after nearly eight years of George W. Bush.

"They have an iron-fisted grip on your democracy," roared Edwards at the Boone event, referring to the insurance, drug and oil companies he has railed against for months. "I am not going to allow corporate greed to steal our children's future."

Edwards is also relying heavily on his personal story -- his father's work in a mill, his humble upbringing -- to speak to rural voters who are already inclined to be for him. Edwards appears to be be running strongest in rural areas in the western part of the state. It is no accident that his schedule yesterday took him to Carroll, Denison and Sioux City -- all in western Iowa.

Edwards's staying power has forced a recalculation on the part of Obama who at one time expected the caucuses to turn into a two-person race between him and Clinton. Instead, Obama now finds himself in an unexpected fight for the anti-Clinton vote with the increasingly feisty Edwards. Hoping to slow Edwards's momentum, Obama and his campaign have begun questioning whether Edwards is in fact an agent for real change in the political system by focusing on the amount of outside money being spent on behalf of the former North Carolina senator.

Obama is also seeking to draw contrasts between the paths that he and Edwards took to get to this place. At the rally last night in Indianola, Obama noted that he eschewed the chance to go to a high-powered law firm in order to become a community organizer -- drawing an implicit contrast with the affluence accrued by Edwards as a trial lawyer. (A side note: Obama is starting to use the term "trial lawyer" more often on the stump to describe Edwards, perhaps hoping to capitalize on the negative associations many voters have with that particular profession.)

While Obama and Edwards are clearly fighting over a similar pool of voters, Obama's strength is consolidated in the more urban eastern part of the state where the state's liberal base is primarily gathered.

As Obama and Edwards fight, Clinton is seeking to close the deal with an appeal to voters' pragmatism. In her own comments as well as those made by her husband, she is focused on convincing voters that serious times call for a serious politician -- one who has been tested before and knows what to expect once in office.

At the same time, the Clintons are trying to portray their Democratic rivals -- particularly Obama -- as risky choices for voters at a time when steadiness and dependability are crucial. Hillary Clinton today told USA Today that she was "not asking voters to take me on a leap of faith" and last night former president Bill Clinton spent 20 minutes detailing his wife's record of accomplishments dating to when the two met in law school. "She never picks up a problem that isn't better when she put it down," he said.

Anecdotal evidence points to a small gain for Clinton over the weekend, gains potentially attributable to the assassination of former Pakistani Prime Minister Benzanir Bhutto and the foreign policy discussion it triggered. But, it's important not to overstate that movement; senior strategists for each of the three campaigns acknowledge the race is stunningly close and that any of the trio could wind up on top or in third place on Thursday night.

REPUBLICANS

If the Iowa caucuses had been held a week ago, there seems little argument that Huckabee would have won. On the shoulders of evangelical voters, Huckabee had passed Romney in most polls and seemed to be growing in strength beyond all predictions.

But then Romney's negative ads started to penetrate the collective consciousness of Republican voters. Romney has attacked Huckabee relentlessly on television for the past several weeks for his record on crime and illegal immigration -- two touchstone issues for Republican base voters.

Although voters insist they dislike negative ads and pay little attention to the claims made in them, the exact opposite is true. Negative ads are run because they work. And thanks to Romney's assault on Huckabee, the former Massachusetts governor has clawed back into the lead in Iowa thanks in large part to an erosion of Huckabee's support among evangelical voters.

Romney's ads have been all the more effective because Huckabee has chosen not to respond to them with ads of his own -- although word out of Iowa this afternoon was that the former Arkansas governor was -- finally -- going negative on Romney.

Why didn't Huckabee respond sooner? We don't know for sure, but two factors contributed to that decision.

First, Huckabee has struggled throughout the campaign to raise the millions of dollars that would allow him to compete on semi-equal turf with Romney. That funding deficits means that even if Huckabee had hit back against Romney earlier it would likely have been drown out by the flood of Romney advertising.

Second, Huckabee's momentum in Iowa was due in large part to the sense of hopeful optimism that surrounded his candidacy.That sentiment grew organically, but because Huckabee did almost no paid communication (TV, radio, direct mail, phone calls) to reinforce the idea with voters, he was decidedly susceptible to a quick reversal in voters' ideas about him. If he had pivoted to a negative campaign against Romney earlier, it might have undone in a moment all of the good will he had built up.

Huckabee has done himself no favors over the past week either, repeatedly flubbing details about the situation in Pakistan following Bhutto's assassination and, in the process, raising questions in voters' minds about whether he is up to the job. Remember that the final days of any race is when voters are really paying attention and trying to decipher which of the candidates they can see being president. Huckabee's slips on Pakistan are amplified given that context.

With Romney and Huckabee essentially tied in recent polling, turning out committed supporters is at the heart of each man's "win" strategy.

It's an open secret that there is no comparison between the field organizations built by Huckabee and Romney. Romney's is state of the art, well financed and tested; his strong win at the Iowa Straw Poll in August proved that his strategists knew how to find and turn out their backers.

Huckabee's organization, on the other hand, is an organization only in the loosest sense of the word. It is cobbling together of evangelical churches, home-schoolers and other allies of the former governor. But, there is very little cohesion between the various groups working for Huckabee -- no unifying force.

Today, the momentum and organizational strength clearly favors Romney. But, Huckabee has made himself a viable candidate in this contest largely on the strength of his personality, which remains his strongest selling point in the final hours of the race.