DES MOINES, Iowa (CNN) -- In the race for the White House, each party has one candidate who might shake things up.
Former Sen. John Edwards is in a three-way tie with Sens. Hillary Clinton and Barack Obama in Iowa.
On the Democratic side, it's former Sen. John Edwards of North Carolina. In the Republican contest, it's Sen. John McCain of Arizona.
In the battle for the Democratic nomination, Sens. Hillary Clinton of New York and Barack Obama of Illinois have been getting most of the attention. They're the national front-runners, and most of the charges and countercharges have been between them.
But in Iowa, the first state to vote, it's a three-way race between Clinton, Obama and Edwards.
Edwards, who came in second in Iowa in 2004, is betting heavily on the Hawkeye State in 2008.
"John Edwards, we have to remember, never really left after the 2004 caucus cycle. He had a good strong organization here in Iowa," said Dennis Goldford, a political science professor at Drake University in Des Moines.
After some initial missteps -- such as his $400 haircut -- Edwards has adopted a strong populist message he calls "America Rising." He says he has the life experience to lead a middle-class uprising against special interests.
"I have fought for jobs for the middle class and health care. I've fought for the kind of working people in the middle class that I grew up with," Edwards said recently.
If he wins the January 3 Iowa caucus or comes in second, suddenly Edwards, instead of Obama, would become the Clinton alternative. Watch how the wild cards could shake up the race »
In the Republican race, the focus has been on the hot contest in Iowa between former Massachusetts Gov. Mitt Romney and former Arkansas Gov. Mike Huckabee.
Romney led most polls in Iowa until recently when Huckabee surged into the lead and became the focus of attacks from the former front-runner.
Huckabee said recently, "The attacks are dishonest and they're desperate. You know why? Because we're winning in this campaign, and there are some folks who don't like that.''
McCain was written off last summer when his campaign nearly ran out of money. But it may be coming back to life, particularly in New Hampshire. That's where McCain won the endorsement of the Manchester Union-Leader, an influential conservative newspaper, and the senator has been gaining in polls there.
McCain is running a strong second in the Granite State. He beat President Bush there in the 2000 primary when he was the maverick. Now he's the candidate of experience.
"It really has a lot to do with experience, knowledge and background that I have on national security issues throughout my entire life," McCain said recently.
Republicans have mixed feelings about McCain.
"His two main issues cut in opposite directions. Republicans don't like his stance on immigration. They do like his support for the war in Iraq, particularly the surge," Goldford said.
Those are the same feelings Republicans have about Bush.
If McCain wins New Hampshire, the Republican race will look totally different, and an Iowa win for Edwards could put a new spin on the Democratic race. E-mail to a friend
All About Iowa • U.S. Presidential Election