While the state has long played a key role in choosing the Democratic presidential nominee, it has unparalleled influence this year, even after several larger states moved up their contests to try and muscle in. Those efforts have done little more than compress the calendar into a five-week sprint that ends with the multistate primary Feb. 5 -- strengthening Iowa's position as the leadoff caucus state rather than diminishing it.
Even New Hampshire, which holds the first primary of the season, has seen its once-mighty position diminished somewhat by Iowa's outsized role this time.
Hillary Rodham Clinton, Barack Obama and John Edwards are locked in a tight three-way contest in Iowa just days before voters attend their precinct caucuses on Thursday. And while all three have strong organizations in other early states, the best laid plans in those places could come apart depending on what happens in Iowa.
Only Obama and Clinton have raised enough campaign cash to be sure of being competitive through Feb. 5 and beyond. Edwards has agreed to accept federal matching funds, which will constrain the amount of money he is allowed to spend in each state.
Trailing in the polls, Bill Richardson, Joe Biden and Chris Dodd have also concentrated nearly all their resources in Iowa in hopes of scoring an upset.
The impact of unexpected news events, such as the assassination of former Prime Minister Benazir Bhutto in Pakistan, may further complicate a fluid situation.
Here's a look at what to expect in the next several weeks:
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IOWA -- Jan 3 (45 pledged delegates)
All six major Democratic candidates will blitz the state before next Thursday's caucuses. Hundreds of staff and volunteers from each campaign will flood likely caucus goers with mail, visits and phone calls. The television airwaves have been saturated for weeks with advertising.
Clinton, who has struggled in Iowa despite leading the field in national and most other state polls, has the most riding on the outcome here. A win could fuel a wave of momentum for the former first lady, while a loss, particularly to Obama, would shatter the notion of inevitability she has tried to project.
The New York senator is barnstorming the state and has deployed dozens of surrogates including her husband, former President Bill Clinton. Her closing argument -- "It's time to pick a president" -- underscores her central message: A candidate like Obama may inspire and move voters, but Clinton is the best prepared to actually do the job.
Obama and Edwards are competing to be the strongest "anti-Clinton" candidate in the field. Both are promising to bring fundamental change to Washington.
Edwards' base of support lies with caucus goers who were with him when he ran for president in 2004. Obama and Clinton are competing for newcomers -- hers are mostly older and female, his are younger and male.
Spending by outside groups has added a new dimension to the contest. EMILY'S List, AFSCME and the American Federation of Teachers are coordinating to boost Clinton through mail, TV and phone banks, while Edwards is receiving assistance from labor-backed groups headed by his 2004 campaign manager.
Obama has called on Edwards to ask the groups to cease their work in Iowa, and privately Obama's advisers fret that he is being hurt by the influx of spending on the other candidates' behalf.
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NEW HAMPSHIRE -- Jan. 8 (22 pledged delegates)
The candidates are reinforcing their organizations in New Hampshire to prepare for whatever verdict Iowa delivers.
The Clinton campaign, which had long counted on the state to be its firewall in the event of a less-than-stellar Iowa showing, has scrambled as her lead here has all but evaporated. The situation was further roiled when a prominent New Hampshire supporter, Bill Shaheen, stepped down as a campaign co-chairman after raising concerns about Obama's teenage drug use.
But Clinton has strong ties to the state thanks to her husband's 1992 and 1996 campaigns. Her organization numbers several hundred staff and volunteers in New Hampshire, methodically working phones and canvassing.
Obama strategists say the key to victory in the state lies with independents who can vote in either the Democratic or Republican primary and who polls show strongly oppose the Iraq war. The campaign is counting on a strong showing among these voters but is targeting traditional Democrats as well, making about 20,000 calls a night.
The Edwards campaign says it has four times the staff in New Hampshire that he had in 2004, when he finished a disappointing fourth. The campaign says its volunteers have knocked on 235,000 doors in the state, where 220,000 people voted in the primary four years ago.
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MICHIGAN -- Jan. 15 (128 pledged delegates; national party says the state will lose them all)
The Democratic candidates have agreed not to compete in Michigan because the state moved the date of its primary in violation of party rules. The Democratic National Committee has penalized the state by stripping all its delegates, but the eventual nominee may choose to restore the delegates prior to the convention next August.
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NEVADA -- Jan. 19 (25 pledged delegates)
Nevada will be the first state with delegates at stake after the New Hampshire primary and could play an important role if the race is still competitive coming out of Northeast.
While party leaders estimate only about 40,000 voters will take part in Nevada's caucuses, all the major candidates have spent considerable resources here in hopes of securing a win among a Western, heavily Hispanic electorate.
The campaigns are all counting on momentum and strong organization to fuel their efforts here. The candidates are basing their organization on an Iowa caucus model, building relationships precinct by precinct.
Richardson has spent more time here than any other candidate, hoping to parlay his Hispanic heritage and proximity as governor of neighboring New Mexico into a strong showing.
All the campaigns are vigorously competing for the backing of the Culinary Union, which represents some 60,000 service workers along the Las Vegas strip. The union will announce an endorsement in early January.
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SOUTH CAROLINA -- Jan. 26 (45 pledged delegates)
The three top-tier candidates have grounds to lay claim to South Carolina -- Obama and Clinton because of their popularity among black voters, Edwards because he was born in the state and won its primary four years ago.
Clinton and Obama have strong organizations in the state and have begun sustained television advertising recently. Both have made a concerted effort to woo black voters, who were 50 percent of primary voters in the state last time; they've run ads on black radio and sought endorsements from community leaders and black legislators.
Edwards has run television ads here since November and has made more campaign visits than Obama or Clinton. Polls show him running a distant third but slowly gaining ground.
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FLORIDA -- Jan. 29 (185 pledged delegates, may be lost)
Like Michigan, Florida has been penalized for moving its primary in violation of party rules. The national party has stripped the state of its delegates, and the candidates have pledged not to campaign in the state, although they have made several fundraising visits.
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MEGA TUESDAY -- Feb. 5 (At least 20 states and 2,075 pledged delegates)
Contests from Connecticut to California on this day could end up determining the Democratic nominee.
Clinton has seen her lead diminish somewhat in California, whose 441 delegates represent the day's largest prize. But the campaign is running generally strong there and is targeting absentee voters who can begin casting ballots Jan. 8.
The campaign is also building organizations in states holding caucuses on Feb. 5, including Minnesota, Colorado and Kansas.
Obama has bolstered efforts in California, and polls show him running strong in Georgia and Missouri. He's strongest in his home state of Illinois, while Clinton is dominant in her home state of New York and in nearby New Jersey.
