Democrats vying for the first prize of the campaign went to Iowa, clear about their target, "there are differences between Senator Clinton and myself on the war in Iraq. I am not in favor of continuing combat missions in Iraq," said Democrat Presidential Candidate John Edwards.
The latest Des Moines register poll shows Clinton taking the lead with 29 percent of likely caucus goers while Barack Obama and John Edwards trail her in a statistical tie.
"I hope that you'll sign up to caucus for me and I hope that you'll get involved in my campaign," said Democrat Presidential Candidate Senator Hillary Clinton.
Clinton's campaign has focused on boosting her appeal in Iowa.
Two appearances this summer with her husband appear to have paid off, leading rivals to turn up the heat.
"Who got the single most important decision since the end of the Cold War right and who got it wrong?" said Presidential Candidate Senator Barack Obama.
At least one republican is targeting Clinton too, to try to win GOP support, "every poll shows that I would be by far the strongest candidate against Hillary Clinton," said Republican Presidential Candidate Rudolph Giuliani.
The latest poll shows Iowans do worry that Clinton is polarizing, but fellow democrats are working to overcome liabilities as well.
"Iowa is a crucial state for people trying to stop Hillary Clinton. If she wins the Iowa caucuses, the race for the Democratic nomination is in all likelihood over that night," said CNBC Chief Washington Correspondent John Harwood.