In Iowa, Clinton Intensifies Attacks

"I think Obama is a little more exciting," Oehlerking said. She left halfway through the Clinton event.

Advisers to rival campaigns said they have seen signs of panic from the Clinton campaign in the wake of a disappointing debate performance at the end of October. Joe Trippi, Edwards's campaign manager, said it was revealing that Clinton made fun of Obama for citing his childhood in Indonesia as part of his experience around the world.

"If she was up by 20 points, I doubt those words ever would have crossed her lips," said Trippi, who managed Howard Dean's losing campaign in 2004. He said he detected a "sense of foreboding" from the Clinton campaign after having failed to gain ground in recent weeks.

The campaigns of all three front-runners predict that as caucus day draws closer, the second-tier candidates will begin to lose support to the top three. New Mexico Gov. Bill Richardson, who has consistently polled in fourth place, packed in eight campaign stops on Saturday, four on Sunday and another three scheduled for Monday.

"I feel that Iowans are taking a second look at other candidates like myself because they're getting tired of the Washington media and the pollsters saying the race is over and Senator Clinton is the victor," Richardson said in an interview Sunday. "There's a real undercurrent here of shopping around."

Staff writer Michael D. Shear contributed to this report from Iowa.