And things are getting nasty. An often edgy Howard Dean responded late Monday to recent attacks on his record on race with a warning shot to the entire field.
"I'm going after everybody. I'm tired of being the pin cushion here. If you do that to me long enough I'm going to respond and I am now," said the former Vermont governor.
Despite the stump speeches and record spending on TV ads, an estimated 20 to 40 percent of Iowans remain undecided, many overwhelmed by leaflets and phone calls from campaigns.
Asked what will have to happen for her to decide, one Iowa voter replied, "Stop calling me!"
Iowans aren't easily agitated -– or impressed by outsiders. It's a workingman's state that fancies blue-collar candidates.
North Carolina Sen. John Edwards, who's surged in the polls recently, picked up a major endorsement Sunday from the Des Moines Register, the largest newspaper in the state. In need of a top-three finish here, he can't make a campaign speech without mentioning his roots.
"My dad was a mill worker," Edwards says. "Those kind of values and belief systems resonate in a place like Iowa."
The same is true for Midwestern favorite son Rep. Dick Gephardt of Missouri.
"I grew up poor," says Gephardt. "My dad was a truck driver."
Gephardt won the Iowa caucuses in 1988. By most accounts, he must win again or his White House hopes are over.
Nationwide, roots may not mean much. But here in Iowa, in Middle America, where a man comes from still matters.
"Unless you've been raised poor, you do not know what it is to be poor," says Iowa voters John Ferrari, Jr.
Whichever candidates come out of Iowa with momentum they'll still have to face a surging Wesley Clark.
The retired general, who is not campaigning in Iowa, has put away his dark suits for argyle sweaters. He's spending time and money in New Hampshire.
But first up: Judgment Day in Iowa, one week away.