Democrat Hillary Clinton's loss to Barack Obama in Iowa has punctured the air of inevitability her US presidential campaign had sought to project and leaves her fighting for her political survival.
The New York senator faces her next test on Tuesday in New Hampshire, where fellow Democrat Mr Obama has been threatening her lead in the polls.
Democratic presidential candidate Senator Hilary Clinton addresses supporters with her husband, former president Bill Clinton, after her defeat in the Iowa caucus in Des Moines
Iowa was the first state contest for both the Democratic and Republican party nominations. The prize is valuable momentum and at least a temporary claim to the front-runner's slot in the campaign ending in a November 4th election.
The winner of the November election will succeed George W. Bush as president in January 2009.
With former president Bill Clinton at her side, Ms Clinton told supporters in Iowa that Democrats needed to nominate a candidate "who will go the distance and who will be ready to lead on day one".
"I am ready for that contest," she said.
"We're not just trying to elect a president, we're trying to change a country. That is what I'm committed to doing. I am so ready for the rest of this campaign, and I am so ready to lead. We have a long way to go, but I am confident and optimistic - both about the campaign and our country," she said.
Mr Obama (46), a senator from Illinois who if elected would become America's first black president, won out among Iowa's mostly white Democratic voters over former North Carolina senator John Edwards (54) and Ms Clinton (60), who finished third.
"Our time for change has come," Mr Obama told supporters after his victory became known.
The Clintons have tried to raise doubts about Mr Obama's experience. Mr Clinton scoffed at Mr Obama as a risky, inexperienced choice, wondering aloud whether Americans would want to "roll the dice" on him.
Agencies