Jan. 3 (Bloomberg) -- Over the past three years, no presidential hopeful has invested more in Iowa than Democrat John Edwards, the only leading candidate to visit all 99 of the state's counties. And none has changed more, from the sunny optimist of his 2004 White House bid to an angry, anti-corporate populist.

``That's what this fight is about for us, it's about stopping corporate greed,'' Edwards told about 50 supporters who turned out to see him at 2:30 a.m. yesterday in Creston, the midpoint of a 36-hour bus tour through 15 counties.

As Iowans gather today for their first-in-the-nation voting contest, Edwards, 54, may be the candidate with the most at stake. He is counting on a victory in the state's caucus to help him build momentum against the Democratic front-runners, Senators Hillary Clinton of New York and Barack Obama of Illinois, in the next round of voting.

A defeat may doom his candidacy. ``He pretty much has to win Iowa,'' said David Redlawsk, a professor of political science at the University of Iowa in Iowa City.

Edwards, who was Massachusetts Senator John Kerry's vice presidential running mate in the last election, began to seek out Iowa's voters long before he formally became a candidate in this year's contest, visiting the state 15 times between the end of the last campaign and the start of this one. Hours after officially announcing his candidacy on Dec. 28, 2006, he flew to Des Moines for his first campaign rally.

Small Towns

Since then, he has spent 86 days in Iowa, compared with 89 for Obama and 72 for Clinton. His extensive time in the state has allowed him to visit some small towns multiple times; on Dec. 30, for example, he returned to the same banquet room at Cronks Cafe in Denison where he held a rally in August. Yesterday, he paid a sixth visit to Ottumwa, a small town south of Des Moines.

Edwards began his campaign last year as a familiar face in Iowa with a campaign organization left over from his second- place finish in the 2004 caucus. He started out tied with Obama, 46, and ahead of Clinton, 60, though he fell behind as his rivals began regular campaigning in the state and raised and spent far more money.

Now, according to a Bloomberg News/Los Angeles Times poll conducted at the end of last month, Edwards, Clinton and Obama are statistically tied. A separate survey by the Des Moines Register found Obama with a lead just outside of the poll's margin of error.

`Dead Heat'

``This is still a dead heat,'' Redlawsk said.

To woo Iowa's voters, Edwards has sharpened his attacks on corporate interests and lobbyists. ``Corporate greed is destroying the middle class, destroying American jobs and destroying your children's future,'' he told supporters in Ames on Jan. 1.

At other stops he has blamed multinational companies and entrenched Washington interests for blocking universal health care and pushing through trade deals that have cost Americans jobs.

``We have to stand up to these people,'' Edwards told about 500 Iowans in Boone on Dec. 30. Two days later, at a retirement home in Fort Dodge, he said special interests have an ``iron- fisted control of our democracy'' and Americans ``need to recognize what a battle we have in front of us.''

`Poverty Tour'

David Bonior, Edwards's campaign manager and a former congressman, said the combative tone arose from trips Edwards has taken around the country, including a ``poverty tour'' last year and numerous visits to areas devastated by Hurricane Katrina.

``People understand what's been going on, that the working and middle classes are getting screwed,'' Bonior said in an interview. ``His message resonates with people.''

Dawn Rankin, 43, who came out to hear Edwards speak in Knoxville on Dec. 29, said he is the right man to take on special interests because he fought against many of the same forces in his previous career as a trial lawyer.

``He's been doing it for 20 years so I don't think it's BS,'' she said. ``He's not just saying what people want to hear.''

The tough talk, however, doesn't appeal to all Iowans. Dale Evans, a 54-year-old factory worker from Cedar Rapids, said that as president Edwards might have trouble working with corporate America after attacking those interests so relentlessly on the campaign trail.

`Harsh' Rhetoric

The Des Moines Register, Iowa's largest newspaper, came to a similar conclusion. Edwards's ``harsh anti-corporate rhetoric would make it difficult to work with the business community to forge change,'' the newspaper said in a Dec. 15 editorial endorsing Clinton.

While a second- or third-place finish in Iowa might fatally wound Edwards's campaign, outright victory wouldn't guarantee an easy road to the Democratic nomination. In New Hampshire, which holds its primary Jan. 8, he trails both Clinton and Obama by more than 10 percentage points.

``Even if he quote unquote wins in Iowa, I don't know if that's going to produce a sudden turnaround,'' said Steffen Schmidt, a political science professor at Iowa State University in Ames.

To contact the reporter on this story: Nicholas Johnston in Creston, Iowa at njohnston3@bloomberg.net.

Last Updated: January 3, 2008 00:10 EST