(7:01 p.m. ET -- Current temperature in Des Moines: 28 degrees Farenheit, feels like 18 degrees with wind chill. Mostly cloudy with a 13 mph wind from the South. )

(8:03 p.m. ET)

The countdown begins in the first test of the presidential campaign, as candidates and caucus-goers alike headed out to the precincts Thursday evening in freezing, blustery Iowa weather.

Hoping to persuade last-minute undecideds, candidates are greeting Iowans on site.

Hillary Clinton just left a caucus site at an elementary school gym in Des Moines, where she shook hands with those lined up in the hallways.

She said she was feeling "great," and was in and out in five minutes

"This is so exciting to see this in person," the Democratic New York senator said.

Republican Mitt Romney just visited caucus-goers at Waukee High School. He appeared upbeat, but was outdone by the enthusiastic crowd.

He shook some hands, posed for pictures and then was gone. He didn't address the crowd, but gave thanks and asked them to get out and vote.

Of the 2 million registered voters in Iowa, less than a quarter-million are expected to caucus. But at precinct #64 in Des Moines, turnout already exceeded the expected 10 percent. With turnout nearing 40 percent there, officials even allowed residents to register to caucus beyond the 7 p.m. local deadline.

There are 1,781 total precincts throughout Iowa.

Romney Denies Dirty Tricks Charges ... Again

By FOXNews.com (6:46 p.m. ET)

Mitt Romney's campaign again denied charges from Mike Huckabee's camp Thursday that the Republican presidential candidate had anything to do with phone calls going out to Huckabee's Iowa supporters giving them incorrect caucus locations.

Romney aides denied the charge, first issued Wednesday, and issued a new statement Thursday afternoon saying:

"This is a reckless and irresponsible accusation, especially (because) we have received reports from Romney supporters who have gotten calls providing inaccurate information about the Governor and caucus locations. There is no excuse for these types of activities and they have no part in the caucus process."

Huckabee's Iowa director Eric Woolson told FOX News Thursday mailers have been distributed giving Huckabee supporters "erroneous information" about their caucus locations. Woolson was very explicit about who's to blame.

It's "obvious that Romney's campaign is trying to suppress Mike Huckabee's turnout by steering our supporters away from their actual precinct locations, trying to make this harder for them," he said.  

With just over an hour to go until voting begins in Iowa, Huckabee's campaign chairman Ed Rollins is already predicting victory -- by "four, five points."

Romney and Huckabee are statistically tied in Iowa polls, and have been at each other's throats since the weekend, when Huckabee aggressively stepped up his attacks, suggesting Romney was being "desperate and dishonest" by airing ads critical of Huckabee.

A Last-Minute Obama Boost?

By FOXNews.com (3:23 p.m. ET)

Barack Obama might be the recipient of some last-minute love from his Democratic rivals in the Iowa caucuses that could give him the push he needs to win Thursday night, according to new reports.

The wrangling comes over the arcane viability rules distinct to the Iowa Democratic caucuses, in which candidates must receive an initial 15 percent support from participants to go onto second-round voting.  (Confused? See 'What's a Caucus' video on http://elections.foxnews.com/iowa/)

Following earlier reports, The New York Times "The Caucus" blog reports that New Mexico Gov. Bill Richardson and Illinois Sen. Obama have worked out a plan where Richardson's campaign will ask its supporters to caucus for Obama should Richardson not meet viability. According to an Obama campaign source: In return, in precincts where Richardson has a chance and Obama has votes to spare, he'll lend them to Richardson.

Late Wednesday, the Iowa Independent blog late Wednesday cited two anonymous sources familiar Richardson's campaign who said organizers also have been instructed to redirect support for the Illinois senator.

Officially, the Obama and Richardson campaigns deny the reports. Richardson also told FOX News he absolutely will not ask supporters to caucus for Obama.

The Washington Post's "The Trail" blog earlier Thursday reported that Delaware Sen. Joe Biden's campaign is in discussions to direct its supporters to Obama should Biden not make the cut. Biden, the Post says, is motivated to stay ahead of New Mexico Gov. Bill Richardson and make the cut to stay in the upcoming weekend debates.

Biden's campaigns also denied the plans, but should the Richardson or Biden plans become reality, they would join Rep. Dennis Kucinich. His campaign already has indicated that it would direct its support to Obama should Kucinich fail to win viability in Thursday's polls. (Obama and Kucinich see eye-to-eye on the Iraq war. Before gaining his Senate seat, Obama said he was opposed to the war; Kucinich voted against the war resolution and has not voted to approve funding for Iraq.)

All three have a high hurdle to leap to surpass the viability requirement, but should their supporters all stand behind one candidate, it could prove decisive.

The Real Clear Politics Iowa average shows Biden polling in a distant fourth place at 5.4 percent, and Richardson close behind at 5.2 percent. Kucinich isn't registering on the average. In the most recent Iowa poll (American Research Group; Dec. 31-Jan. 2; 415 likey voters), he pulled 1 percent of the survey.

But the space between the top candidates leaves little room for error.

Obama's average numbers are leading the Democratic field 30.8 percent; Hillary Clinton follows at 29.2 percent, and John Edwards takes third at 26.0 percent.

Once More, Obama Shoots Down Religion Rumor

By FOXNews.com (5:18 p.m. ET)

Barack Obama just can't seem to shake questions about his religion -- not even on caucus day.

The Illinois senator -- whose middle name is Hussein -- has had to shoot down rumors throughout the campaign that he's a Muslim, and on Thursday while visiting a downtown Des Moines food court another woman asked him about his faith.

This time, the question was whether he is an atheist.

"I'm a member of the Trinity United Church of Christ," Obama replied. "Don't read e-mails."

He was referring to e-mails that falsely suggested he was linked to Islamic extremists, and which were forwarded by volunteers for Hillary Clinton's campaign. Those volunteers were forced to resign.

The Illinois senator has had to give the religion response several times. As Obama has previously explained, his stepfather whom he lived with in Indonesia as a child was Muslim, but he is a Christian who regularly attends church.

Meanwhile, Obama was greeted Thursday in Des Moines by a throng of well-wishers, who said he inspired them and promised to caucus for him.

"You are going to win big," one supporter told him.

Clinton Clan Lunch Break

By FOXNews.com (4:21 p.m. ET)

Hillary Clinton, with her family in tow, hit up Tursi's Latin King restaurant in Des Moines for a caucus-day lunch Thursday.

The whole Clinton clan was there -- Bill, Chelsea and even Hillary's mother Dorothy Rodham.

Supporters flocked to the candidate, and one, Diane Bishop, was so overwhelmed she began to cry.

Ever the micro-manager, Bill Clinton seemed to facilitate photographs of the moment, asking staffers, "You don't want them to shoot this?" as they were trying to move press out of the way.

For those interested, Hillary Clinton ordered hot sausages, while Bill ordered capellini with no white sauce: "It upsets my stomach."

Daughter Chelsea ordered a plate of steamed veggies.

Hey Huckabee, Watch the Hair ...

By FOXNews.com (2:05 p.m. ET)

Mitt Romney showed a little good humor Thursday morning after rival Mike Huckabee's man-behind-the-curtain -- campaign chairman Ed Rollins -- talked about knocking Romney's teeth out in a Washington Post article.

Romney responded at a stop in Des Moines, Iowa, continuing the back-and-forth between him and the former Arkansas governor, who are locked at the top in Iowa.

"The politics are getting interesting," Romney said. "Tensions are getting high and comments are being made that are really quite questionable. I saw just yesterday the chairman of Governor Huckabee's campaign said that he would like to knock my teeth out. My only comment on that is, Don't touch the hair."

The retort got laughs. After all, it showed Romney was willing to shrug off for a moment the dogging perception that he's a too-perfect, plastic candidate.

The millionaire businessman also defended his history in the private sector, saying he understands why jobs come and go.

The comments came after Huckabee said in Burlington, Iowa, "I think sometimes the reason I'm catching fire is that people would rather elect a president who reminds them of the guy they work with -- not the guy who laid them off."

Ouch.

That was on top of Rollins' comments. He told the Post in an article Wednesday, "What I have to do is make sure that my anger with a guy like Romney, whose teeth I want to knock out, doesn't get in the way of my thought process."

Giuliani's N.H. Balancing Act

By FOXNews.com (12:47 p.m. ET)

Republican presidential candidate Rudy Giuliani spent his morning far from the heartland plains, seeking votes instead in the place he thinks he has a better chance: New Hampshire.

At the Segway Inc. factory in Bedford, N.H. -- yes, the same Segway that makes the two-wheeled, self-righting scooters -- Giuliani defended his strategy focusing away from Iowa. Asked by a reporter if he was nervous about skipping Iowa on their big day, he said he was not.

"This is the strategy we selected pretty close to Day One, so maybe other people would get nervous in a situation like this, but this is what we expected. ...

"And here's why we made that decision: Absolutely no insult to Iowa at all -- the reason for it is, we see this as a different kind of an election, different kind of primary election. You've never had 29 primaries and caucuses in one month. It's extraordinary. Something different is going to win this election.

"We hope it's our different strategy that wins, and we're confident it will. If it isn't our different strategy, something else different is going to win."

Describing his plan as a "proportionate approach," Giuliani said he's made an early focus on Florida because voting has already begun there. He has been spending time also in South Carolina, Missouri, California and Illinois.

But after a short trip to Florida Thursday night, Giuliani will be on a plane back to campaign the final days in New Hampshire, where the race is increasingly looking like a two-man race between his rivals Mitt Romney and John McCain. The latest Real Clear Politics poll average puts Giuliani (10 percent) behind McCain (31.3 percent) and Romney (28.8 percent) there.

"I think in these last few days, you're gonna see us have a strong finish in New Hampshire," Giuliani said.

A Case For, and a Case Against Iowa

By FOXNews.com (10:54 a.m. ET)

Some words on Iowa from a couple professional prognosticators ...

The Rhodes Cook Letter, by Rhodes Cook: "[T]he current reality will be superseded by the results from the Iowa caucuses on Jan. 3 and the New Hampshire primary five days later. By the morning of Jan. 9, a new pecking order could very well frame both the Democratic and Republican contests for the flurry of events that will quickly follow.

"One critical question that will be answered in short order is whether the Iowa-New Hampshire duo will be merely ‘winnowers' in 2008 or all-powerful ‘deciders.' Four years ago, the two were deciders, giving twin victories to John Kerry that put him on a smooth path to the Democratic nomination.

"In 2000, they proved just as decisive for Al Gore, providing a knockout blow to the ambitions of his prime challenger, Bill Bradley, even though Bradley's loss to Gore in New Hampshire was by a margin of just 4 percentage points (50% to 46%).

"But on the Republican side in 2000, these two early contests merely winnowed the sizable GOP field. George W. Bush carried Iowa, John McCain won New Hampshire - a split decision that ensured the Republican contest would continue in highly competitive fashion between the two. Bush and McCain traded primary victories over the weeks that followed. It was not until the Texas governor dominated the Super Tuesday vote in early March that he was able to finally drive McCain from the race. ...

"In the month ahead, though, it is not really delegates that the candidates are competing for - there are not that many at stake on either side in January. Rather, candidates are vying for momentum, produced by a strong early showing or two. Yet other less desirable outcomes could just as well happen. Candidates that do not break quickly from the gate could be stuck treading water - desperately looking for a venue that could give them traction; or they could be forced out of the race altogether, usually by a combination of poor primary showings and an empty campaign treasury."

Larry Sabato, director, University of Virginia Center for Politics: "I have nothing against the Hawkeye State. To the contrary, my visits there have invariably been pleasant, and my dealings with colleagues and journalists based in Iowa have been delightful.

"It's just that (1) the caucuses this year are way too early; (2) the caucuses and the state are unrepresentative of the broader electorate; and (3) the rules of the caucuses raise real questions about fairness. " More here.

White House Reaction? No Comment

By FOXNews.com (10:25 a.m. ET)

The nation's first politician is staying true to his promise to be quiet about his potential successors, at least for now.

President Bush could be fast asleep by the time Thursday's results are final, White House press secretary Dana Perino said Thursday.

"What time do all the results start coming in? Because he goes to bed early," Perino joked.

Only calling it is a "very exciting time for America," she said Bush only will be watching the race as an observer.

"And the president is watching it as he has been over the past little while, as an observer, as somebody who is obviously very interested in politics. But he's not spending a lot of time on that," Perino added. 

She said the president will not issue any reaction following Thursday's outcome.

Lieberman: Just Glad to Be a Senator

By FOXNews.com (9:56 a.m. ET)

Democratic Sen. Joe Lieberman, stumping in New Hampshire for his pal, GOP Sen. John McCain., sought to lay to rest any ideas that he would join McCain on the ticket should the Arizona senator win the presidential nomination.

Asked during an appearance on FOX News Thursday if he'd join McCain, Lieberman said with a chuckle: "No. There are limits to my loyalty. Also, I think he has much better judgment than that. No, I got the national political bug out of my system" -- a reference to his 2004 bid for the presidential nomination, and his 2000 run with Democratic nominee Al Gore.

And referencing his 2006 independent bid for the Senate after he lost the primary, he said: "You know, I had a near-death experience in my re-election campaign last year. So, I'm feeling so grateful to be a senator from Connecticut. That's all I want to be. But it would be great to be the senator from Connecticut who has a friend named John McCain in the White House."

McCain also got the nod Thursday from the Detroit News, whose editorial page endorsed him.

Thompson Denies Plans to Drop Out

By FOXNews.com (8:55 a.m. ET)

Republican presidential contender Fred Thompson on Thursday denied fresh reports that he might drop out of the race and back Arizona Sen. John McCain as early as this week.

The story, reported by The Politico, cited unnamed sources close to Thompson's campaign, including one adviser who said he might drop out as early as this weekend.

"There is no such Thompson adviser. That's not something that I have thought about. That's not something I have discussed with anybody. It's something made out of whole cloth and dropped at the last minute, probably by one of the other campaigns with some staffers with too much time on their hands," Thompson said.

He admitted, "Everybody needs to reach a certain level, and everybody needs to get their wind at their back from Iowa. i want a strong showing," but said,"We're optimistic and feel good

According to reports in The Politico, what was once the upstart Thompson campaign might soon become the non-start Thompson campaign, a situation that his organization's insiders are handicapping as a boost for McCain.

Thompson advisers said that if their candidate doesn't make third place in Thursday's Iowa caucuses, he could drop out of the race before next Tuesday's New Hampshire primary. And if so, Thompson might throw his support behind McCain, who has seen a recent surge in support in The Granite State.

Click here to read the full report in The Politico.

"Without a solid third-place finish, there's no point in going on," an unnamed Thompson adviser told The Politico. "It was an honorable race, and he turned out to be a good candidate. The moment had just passed."

And another source said there is "a strong likelihood" that Thompson would drop out before the New Hampshire contest if he received less than 15 percent in Thursday -- probably even before the debates this weekend.

The sources said they were not speaking on any specific comments Thompson had made, but rather a general consensus among those close to the campaign.

The Forecast: Brrrrrr!

By FOXNews.com (9:20 a.m. ET)

Iowans are waking up to a chilly blast that is sweeping much of the country. Temps are in the single digits, and won't get above freezing by caucus time (7 p.m. CT, 8 p.m. ET). According to Weather.com: Current temp in Des Moines, 12 F; feels like -3 F; at 7 p.m. CT, 24 F. ... In Cedar Rapids, it's 4 F; feels like -11 F; at 7 p.m., 22 F. ... In Sioux City, it's 18 F; feels like 2 F; at 7 p.m., 27 F. ... Good News: No snow.

Let the Races Begin! Iowans Put Stamp on Wide-Open Race

By The Associated Press (3:24 a.m. ET)

DES MOINES, Iowa -- Presidential hopefuls urged their partisans to brave the cold and rally fellow Iowans to the caucuses Thursday, a massive test of organization that held the key to victory in the first contests of the 2008 election season. Capturing the urgency -- and biting chill -- in the air, Barack Obama implored his people, "Walk quick, talk fast."

Iowans, courted for months by candidates barnstorming their towns, swamping their airwaves and, in the later rounds, bickering with each other, finally give shape to the presidential race in a caucus ritual rooted in a centuries-old tradition of political activism.

Whether they would bring clarity to the national contest as it pivots to New Hampshire only five days later and then on to remaining states was just one more unknown in a campaign unpredictable at every turn.

"The two things that are clear to everyone here is that it's cold and it's close," said former Missouri Sen. Jim Talent, an adviser to Mitt Romney. Romney vastly outspent his GOP rivals, only to see his longtime lead in Iowa polls slip away.

The former Massachusetts governor goes into the caucuses fighting for a win against Mike Huckabee, a man who stood at 2 percent in the polls in Iowa less than six months ago and was a blip elsewhere too until his campaign took off.

Polls indicate an improbably tight three-way race for the Democrats, Hillary Rodham Clinton, Obama and John Edwards all knotted together -- a crowd-pleasing nail-biter reflected in swollen crowds at Democratic venues and expectations of a hectic caucus night.

Caucuses begin at 7 p.m. -- 8 p.m. EST -- and with that evening curtain-raiser, most candidates filled their Thursday calendar with still more speeches and events.

But while the talk goes on past one more sundown, the time for listening was fast drawing to a close. The persuasive power of rhetoric was suddenly yielding in importance to the availability of baby sitters to help people get to the caucuses.

Campaigns were ready with snow shovels if needed, and used the phone and Facebook online to encourage voters. Romney said his campaign made 12,000 calls on Sunday alone.

Obama, an Illinois senator, recommended longjohns as he sent people door to door. Clinton, in her historic run to become the first female president, served bagels, fruit and coffee to Des Moines volunteers and said of the single-digit temperatures, "I know if you're here from Iowa to help me, this is like, nothing."

Surveys suggested a quarter of likely caucus-goers were still undecided in the final days.

Clinton and Huckabee appeared on late night talk shows, a chance to start looking beyond Iowa and endear themselves with a national audience just as the campaign starts to move across the country.

But their different responses to the siren call of Hollywood illustrated the polish of the Democrat's campaign and the occasional muddle of Huckabee's, recurring more often in recent weeks.

Clinton, feet firmly planted in Iowa, spoke by tape with David Letterman, whose New York-based show settled with striking writers. Huckabee flew to Burbank, Calif., to sit with Jay Leno in the final crucial hours of the Iowa campaign and was unaware when he made the commitment that he'd have to cross a picket line. The former Arkansas governor said he supported the strikers; they called him a scab.

Obama, an at-times stirring orator and the most viable black presidential candidate in history, drew large crowds, yet acknowledged that won't put him over the top unless he can motivate his supporters to come to the caucus meetings.

He's proven especially popular among young people, who are notably less apt to vote.

Altogether, 120,000 to 150,000 people were expected to come to the Democratic caucuses and 80,000 to 90,000 to the GOP meetings. Caucuses are held in each of the state's nearly 1,800 precincts and draw anywhere from a few people each in rural areas to hundreds in suburbia.

Former Sen. Fred Thompson of Tennessee hoped to rescue his faltering candidacy with a third place finish against an ascendant Sen. John McCain of Arizona, with long shot Rep. Ron Paul and former New York mayor Rudy Giuliani also in the mix. McCain made a quick return to Iowa on Wednesday after largely bypassing the caucuses to make his stand in New Hampshire.

Giuliani, who has seen his national lead in polls wither, is pinning his hopes on the flood of contests after New Hampshire if he can't get traction in the Granite State, where Romney and McCain are going to head to head.

Edwards, who finished second in Iowa in 2004 on his way to a spot on the national Democratic ticket, mounted a 36-hour marathon capped Wednesday night at a rally with rocker John Mellencamp. The grueling schedule turned Edwards' voice hoarse.

At every stop, the former North Carolina senator tried to turn what some Americans see as a drawback -- his lucrative career as a trial lawyer -- into an asset.

"I spent 20 years in courtrooms" fighting big companies, he told an Iowa City crowd. "You cannot 'nice' these people to death," Edwards said, obviously jabbing at Clinton and Obama's greater willingness to negotiate for change. "They will stomp all over you."

Compiled from staff and wire reports.