When caucus-goers visit one of Iowa's 1,784 precincts on Thursday, they will once again begin the country's time-tested, and at times arcane, process of picking their party's candidate for the White House.
For three decades, the caucuses, which take place in schools, public buildings, churches and private homes, have served as the first trial for candidates seeking the presidency.
Many Iowans appear to be going into this year's caucuses undecided amid an unprecedented onslaught of campaign messages and a crowded field of contenders, said Cary Covington, associate professor of political science at the University of Iowa.
"The intensity of the effort is far and away bigger than anything since '84," he said. "If they don't beak turnout records, I'd be very surprised."
But amid all the attention heaped upon the Hawkeye State by candidates and the media every four years, Iowa's impact on the overall race for the presidency still begs definition.
"[Iowa] gets rid of national candidates who don't have grassroots support once people examine their platforms," said Christopher C. Hull, an adjunct assistant professor in Georgetown University's Department of Government.
The Iowa caucuses' first-in-the-nation status serves not to predict each party's winner, rather to help narrow the choice of candidates for the rest of the country, Hull said.
"Iowa could be a bellwether, but it is not a predictive mechanism," he said. "It winnows the field."
The Iowa caucus tests each candidate's ability to spread his or her message and mobilize supporters -- both important skills for a president, said Hull, author of "Grassroots Rules: How the Iowa Caucus Helps Elect American Presidents."
After candidates have their mettle tested in the Iowa caucus, later primaries then test electability, he said.
"If you switch Iowa and New Hampshire, you have a very different process," he said.
Iowa's mixed track record
In recent years, the Iowa vote has predicted eventual party nominees, picking John Kerry in 2004, Al Gore and George Bush in 2000 and Bob Dole in 1996.
But that was not always the case.
In 1992, Bill Clinton won just 3 percent of the delegates behind Tom Harkin's 76 percent, but went on to secure the Democratic nomination.
Other eventual nominees also didn't finish first in Iowa: George H. W. Bush and Michael Dukakis in 1988, Ronald Reagan in 1980 and Hubert Humphrey in 1972.
Occasionally, Iowa has surprised everybody. In 1988, televangelist Pat Robertson finished second in the caucus behind Bob Dole and ahead of then-Vice President George H.W. Bush.
Republican candidate and former New York City Mayor Rudy Giuliani has eschewed Iowa and New Hampshire this year, focusing his efforts on Florida and states that vote later in the nominating calendar.
That tactic could backfire on him, political scientists told the Online NewsHour.
"If you don't finish in the top three in Iowa, you're not going to be a nominee," Covington said. "At least at one time [Giuliani] was the formidable national frontrunner ... but for whatever reason, he has not made strong effort in Iowa. If that works for him, it will undermine the role of Iowa. But if he [loses] in Iowa and New Hampshire, he looks like damaged goods. People will be suspicious by the time Florida votes."
Hull called Giuliani's decision to skip Iowa "a bad strategy," even though he predicted two years ago that the former mayor and Sen. John McCain, R-Ariz., likely wouldn't focus many resources there.
"Those who skip Iowa pay a very serious price," he said.
Candidates who have previously chosen to bypass Iowa have had high national poll numbers and significant fund-raising abilities -- two things Giuliani has had.
"I don't understand the strategy, but it could work," Hull said. "If it does, it will reshape the way we rethink primary strategy. It's never worked before.
Striking the right tone
In 2004, the race for the Democratic nomination was seemingly between former Vermont Gov. Howard Dean and former Rep. Dick Gephardt, D-Mo., but they finished third and fourth in Iowa, respectively, after negative campaigning between them allowed Kerry and former Sen. John Edwards, D-N.C., to rally.
It is a lesson analysts said this year's candidates took to heart.
"On the Democratic side, you do not see the outright attacks than you saw in '04," Covington said. "They do take shots, but they are relatively more veiled."
Iowa voters have previously punished some candidates for going negative against their opponents, he said.
Hull said the decision for a candidate to go negative is akin to signing a murder-suicide pact. It's obvious from the Democrats' more indirect campaign tactics this year that they learned their lesson in 2004, he said.
"They're careful how they pitch themselves and how they come across. The message is unmistakable, but the words are very polite."
Democratic candidates have another reason not to outwardly criticize each other. They might need their opponents' supporters to support them during a second vote at the precinct level.
If a Democratic candidate doesn't reach 15 percent of the vote in any given precinct, his or her supporters must then select a more viable candidate to support. Supporters of other candidates will approach supporters of non-viable candidates, seeking their support.
"I've never been in a caucus where people were overtly criticizing other candidates," Covington said. "You don't hear a lot of trash-talking of other candidates. It's mostly, 'What issue are you interested in? My guy's better.' It's really a pretty civil process."
On Tuesday, Ohio Rep. Dennis Kucinich asked his supporters to back Illinois Sen. Barack Obama if his candidacy is not viable in their precinct.
Headed into Thursday's Democratic caucuses, public opinion surveys have indicated that Edwards and Obama may be in better shape than New York Sen. Hillary Clinton's campaign when it comes to being a voter's second choice, said Jim McCormick, professor and chair of political science at Iowa State University.
"If [Sen. Joe Biden] or [Sen. Chris] Dodd or Kucinich are not viable, it's probably more likely their supporters will go to Obama or Edwards," McCormick said. "Edwards has a real chance of pulling this off."
Keys to success in Iowa?
After former President Jimmy Carter used Iowa to successfully overcome his "Jimmy Who?" moniker during his 1976 campaign, candidates have spent ever-increasing amounts of time in the Hawkeye State before the caucuses.
Face-to-face meetings rather than mass media still seem to be the best shot at success in Iowa, Hull and McCormick said.
"If Iowa is a contest which focuses on the grassroots, precinct chairmen, recruitment, training, mobilization of ground forces, then spending on TV would tend to harm you," Hull said.
With TV ads, candidates are spreading your message to Iowa's 3 million residents rather than focusing on the 100,000 to 200,000 people who might caucus for their party, he said.
But there is no clear formula for success. Some candidates -- such as Dodd and Biden -- have spent months there before this year's caucuses, but they are still trailing in most polls.
"Retail politics, one-on-one talking to people, is still the currency -- the coin of the realm in the Hawkeye State," Hull said.
Because the sum of delegates picked by caucuses in rural areas outweighs those of Iowa's urban areas, candidates are almost forced to crisscross the state
"It makes the candidates really fan out throughout the state," McCormick said. "That's a herculean task for any candidate with limited resources."