Tim Hagle, a political science professor at the University of Iowa and an active Republican, said Iowa's small size gives candidates a chance to interact directly with voters as they shape their campaigns — "to work the kinks out.... It's not that you want the candidates to pander to these folks, you want them to listen to them."

That means despite the seemingly nonstop campaign commercials on television and radio stations throughout Iowa, candidates who want to motivate voters to invest an evening participating in a caucus must reach out to them in living rooms, diners and town halls — again and again.

Hagle said the independence of Iowa voters more than makes up for the criticism that the state is too white and too rural to represent the rest of the country. "Iowa is a very purple state," he said, neither Republican red nor Democratic blue. About 40 percent of Iowans are independents, registering as having no political affiliation, Hagle said.

The caucus system is complicated and time-consuming, often requiring participants to stand up for their choice of candidate in front of their friends and neighbors. The caucus results in Iowa are not binding on the delegates eventually elected by party members to attend the Democratic national convention in August and the Republican national convention in September, but, Hagle said, still matter.

"In that sense it's still a beauty contest," he said of the GOP caucus. "But you've got to be pretty good-looking to get people out in 1,700 precincts on a cold January night."

Not everyone is a fan of caucuses. Most states, in fact, hold primary elections that allow voters to simply cast a secret ballot at their polling places. Utah's presidential primary is set for Feb. 5, the same day as more than 20 other states nationwide, including New York and California.

Tova Wang, a democracy fellow at the Century Foundation's Washington, D.C., office, called caucusing "a very bizarre process" that attracts only the most committed voters. While Wang said the results of Iowa's caucus votes should not be ignored, they should be put in perspective.

"The rest of the voters throughout the country should realize these are people who may not be representative of the things they care about," she said.

But the results are hugely important to the candidates, who depend on a good showing to keep campaign contributions and volunteers coming in. Romney, for example, has sunk more money and time into Iowa than any other GOP candidate in the hopes of using the state to establish the all-important campaign momentum.

Now, though, Romney is running behind Huckabee in a number of key polls, including the just-released Des Moines Register poll that had been highly anticipated by political watchers. He spent much of the day hitting gatherings of football fans huddled to watch the New Year's Day games.