Amid record turnout, both men won over significant portions of Iowa caucusgoers by preaching change and presenting charismatic personas that struck voters as authentic. Mr. Huckabee, the former governor of Arkansas, made up for a lack of money and a small organization with the fervor of his supporters, many of them evangelical Christians like him. Mr. Obama, a first-term senator from Illinois, also enjoyed the most spirited support in his party, drawing massive crowds at rallies and reaching out successfully to young people, independents, and even some Republicans.
"Tonight we proved that American politics still is in the hands of ordinary folks like you," Huckabee said, reflecting the populist bent of his campaign.
Obama's victory speech highlighted his goal of ending divisiveness: "We are one nation," he said. "We are one people and our time for change has come."
The two victors won handily: Huckabee took 34 percent of the Republican vote, versus 25 percent for former Massachusetts Gov. Mitt Romney and 13 percent each for former Sen. Fred Thompson of Tennessee and Sen. John McCain of Arizona. Rep. Ron Paul of Texas, a favorite among libertarian-leaning Republicans and a fundraising phenom in the fourth quarter of 2007, came in with 10 percent.
Obama won 38 percent of the Democratic delegates at stake, against 30 percent for former Sen. John Edwards and 29 percent for Sen. Hillary Rodham Clinton. New Mexico Gov. Bill Richardson came in a distant fourth, with 2 percent. Sens. Joseph Biden of Delaware and Christopher Dodd barely registered any delegates in a Democratic caucus system that requires candidates to meet a 15 percent threshold of initial support to even qualify for delegates. Both senators dropped out of the race late Thursday night, fulfilling Iowa's usual role of winnowing the field.
Both of Iowa's winners, who trailed here until relatively recently, positioned themselves as anti-establishment. Huckabee has never served in Washington, and Obama, the youngest candidate in both fields at 46, has been in the Senate only three years. As an African-American, Obama also cuts a different figure from the usual white male candidate.
But first and foremost, analysts say, it was the desire for change that propelled both men to victory.
"And it's about authenticity," says Mark Mellman, a Democratic pollster not affiliated with any presidential candidate. "It's a buzzword, but the truth is that Romney and Clinton looked to voters like their positions were dictated by polls, not principles.... I'm not saying it's true, but it does seem to be what voters thought."
Also, Mr. Mellman adds, the subtext of Obama's message on his banner – "Change you can believe in" – seemed to be on purpose. "He's saying you can believe what he says," implying that Senator Clinton cannot be believed, Mellman says.
While Obama is now well-positioned to compete in the New Hampshire primary on Jan. 8 and beyond that, with fundraising that has kept pace with Clinton's, he is not necessarily favored to win the nomination. Iowa was just the first round; George H.W. Bush came in third in the Iowa caucuses in 1988 and went on to win the White House. But Obama has succeeded in taking the wind out of Clinton's sails and putting to rest any notion that she was the inevitable Democratic nominee. All along, Iowa has been Clinton's weakest state, and Obama can still expect her to be a formidable opponent.
Mr. Edwards faces a steeper climb heading into New Hampshire. He is less well-funded than Obama and Clinton, and in all likelihood needed to win Iowa to gain traction – and money – for the battles ahead. Edwards came in second in the Iowa caucuses four years ago and became John Kerry's running mate on the Democratic ticket.
Huckabee's victory does little to clarify the Republican field. He has not polled well in New Hampshire, and his biggest impact on that forthcoming contest may be that he has wounded Romney, who led in New Hampshire polls until recently. Senator McCain, who won the New Hampshire primary in 2000, remains popular there and has surged of late. McCain's almost-third-place finish in Iowa, a state where he barely campaigned, could add to his New Hampshire surge. If Romney loses his second contest in a row, after leading in both Iowa and New Hampshire for months, he could have a hard time gaining traction with voters in subsequent contests.
Coming out of Iowa, another big question centers on national frontrunner Rudolph Giuliani, the former mayor of New York. He has followed an unorthodox strategy for primary season: He mostly skipped Iowa, has campaigned sporadically in New Hampshire, and chose to focus on the big, delegate-rich states that vote later in primary season. To him, the first important contest is Florida, which holds its primary Jan. 29. Then he intends to clean up in the populous states that hold their primaries Feb. 5, or "super-duper Tuesday," including California, New York, New Jersey, Missouri, and Georgia. In all, almost two dozen states hold primaries that day.
In national polls taken before the Iowa caucuses, Mr. Giuliani remains at the top – barely – competing most closely with McCain and Huckabee. But his unusual strategy has been risky from the outset, analysts say. If different candidates win the Republican contests before Florida – New Hampshire, Michigan (Jan. 15), Nevada (Jan. 19), and South Carolina (Jan. 19) – then Giuliani's gambit could work.
But "he is not in control," says independent pollster John Zogby. "Meanwhile, one thing is clear: that Giuliani has lost Iowa and he'll lose New Hampshire, Michigan, and South Carolina. Things have to be really in a muddle for this thing to work."
At this stage, it would be foolish to rule out much of the Republican field as potential nominees, says GOP pollster Whit Ayres, who is not working for a presidential candidate. Huckabee, a former Baptist minister, has fought the idea that he could be a "one-state wonder" in winning Iowa, much like the Rev. Pat Robertson, who won Iowa in 1988 on the Republican side, only to fade.
"Nationally, religious conservatives or social conservatives are about one-third of the electorate, and economic conservatives are two-thirds," says Mr. Ayres. "If he ever gets himself in a one-on-one campaign with an economic conservative, he's going to have to expand his coalition very quickly."
But after winning Iowa, Ayres says, Huckabee is still very much in the hunt. Even though the Arkansan trails in New Hampshire, which has a small religious conservative population, he has been leading the polls in South Carolina, even before his Iowa victory.