Democrat Hillary Clinton touted her experience and rival Barack Obama made his case for change yesterday as White House hopefuls scoured Iowa for support one week before the US state's too-close-to-call nominating contest.
Ms Clinton and Mr Obama were among 10 Democratic and Republican candidates who spent the day in Iowa, where next Thursday voters in both parties kick off the state-by-state battle to choose candidates for the November 4th, 2008, election.
Polls show a tight Iowa race on both sides, with Clinton, Obama and John Edwards in a three-way fight among Democrats and Mitt Romney and Mike Huckabee battling for the Republican lead in a state where a win provides vital momentum.
Mr Obama, a first-term US senator from Illinois who has been rapped by Ms Clinton for having too little experience for the job, said he was the candidate who could end the partisan "food fight" and accomplish real change in Washington.
In a speech offering his final argument to Iowa voters, he took swipes at Ms Clinton, a New York senator and former first lady, and poked fun at her husband Bill Clinton's statement that electing Obama would be a roll of the dice.
"The real gamble in this election is playing the same Washington game with the same Washington players and expecting a different result," he said in Des Moines before heading off to campaign stops around the midwestern state.
"You can't fall in line behind the conventional thinking on issues as profound as war and offer yourself as the leader who is best prepared to chart a new and better course for America," he said.
Mr Obama, an early opponent of the Iraq war, has criticized Ms Clinton for voting in the US Senate to authorize it.
He and Edwards, a former North Carolina senator, also have attacked her vote to label an Iranian military group a terrorist organization as potentially paving the way to war with Iran. Ms Clinton did not directly respond to Mr Obama's comments, but slipped in a reference to her experience as she joined other presidential candidates in decrying the assassination of Pakistan opposition leader Benazir Bhutto.
"I have known Benazir Bhutto for a dozen years and I knew her as a leader, I knew her as someone who was willing to take risks to pursue democracy on behalf of the people of Pakistan," she said in Lawton, in northwest Iowa.
She also took a shot at Obama's health care plan, which does not include mandates for participation and which critics say would leave up to 15 million Americans uninsured.
Several top Republicans were notable exceptions to the focus on Iowa yesterday.
Mr Huckabee, the Baptist minister and former Arkansas governor who has been surging in polls, was in Florida but planned to return later in the day. Mr Romney, the former Massachusetts governor, campaigned in New Hampshire, which holds its nominating contest on January 8th, five days after Iowa.
Mr Romney, who along with Mr Huckabee has been criticized for a lack of foreign policy credentials, has seen his lead in New Hampshire evaporating under the advance of rival Arizona Senator John McCain, a former Vietnam prisoner of war and member of the Senate Armed Service Committee.
Former New York Mayor Rudy Giuliani also skipped Iowa on Thursday to campaign in Florida, which holds its contest on January 29th. He returned to a familiar theme, his leadership after the September 11 attacks in New York, in unveiling a new television advertisement to run in New Hampshire and Florida, and on national cable television, featuring images of firefighters at the World Trade Center ruins.
Mr Giuliani, who has seen his lead in national polls shrink and in some cases disappear under the surge from Mr Huckabee, has concentrated