WASHINGTON — He launched his campaign in the hurricane-ravaged quarters of New Orleans and traveled through Appalachia, talking about poverty and railing against corporate greed and financial disparities. But something strange happened as John Edwards built his campaign for president: He drew votes from an economically diverse bloc of voters, mostly white men, who were just as likely to be rich as they were to be poor.

Now that Edwards' departure from the campaign has left a two-person race for the Democratic nomination, Sens. Hillary Rodham Clinton and Barack Obama are trying to figure out how to attract those voters. And because his support was hard to characterize — the one thing it was not was disproportionately poor — his political base is the subject of a scramble.

The latest surveys show Edwards supported by as much as 15 percent of the Democratic vote, enough to make the difference Tuesday when voting takes place in more than 20 states as part of a nationwide primary day. But where these voters' sympathies will lie is a mystery.

"It looks pretty close," said Andrew Kohut, director of the Pew Research Center for the People & the Press. He said the Edwards base would feel "cross-pressured," with men more likely to support Obama and other lower-income voters probably moving to Clinton.

The two senators moved quickly Wednesday to attract that base, adopting pieces of Edwards' populist message.

Clinton, who represents New York, lauded Edwards for making poverty "a centerpiece of his candidacy" and said the issue should be "on the top of the list of American priorities." Obama, who is from Illinois, called Edwards' return to New Orleans a "gracious way to end" his campaign.

But the decision by the former North Carolina senator to leave the race, along with the surprising makeup of his supporters, suggests the fiery populism he brought to the campaign was a doomed strategy from the beginning.

Over time, his initial focus on the poor evolved to issues important to working people and the middle class — a recognition of where the votes would come from.

"When it gets closer to Election Day, it's just pretty hard to stay focused on that (anti-poverty) message when there's another group that's going to be more influential," said Jason Furman, who was policy director for the 2004 Democratic presidential nominee, Sen. John F. Kerry of Massachusetts.

In addition, several analysts who track public opinion on the economy expressed doubt that a focus on poverty, complaints about rising income inequality and a call to dislodge corporate power from Washington would draw substantial numbers of voters.

Poverty and income inequality "may not be the primary thing you want to hang your campaign on," said Harry Holzer, an economist with Georgetown University and the Urban Institute in Washington. "Especially poverty — since it doesn't directly affect most voters, you probably don't want to make that your primary reason for running."

Edwards made poverty a central, animating mission for his candidacy. He also talked often of the problems of working-class Americans, repeatedly reminding voters that his father had been a mill laborer.

Over time, his campaign took on a more emphatic and even angry tone, as he drew pictures of insurance companies denying health coverage that could save patients' lives. He promised to kick corporate interests out of the room when negotiating public policy, saying his hardball tactics would work where his opponents' would fail. "You can't 'nice' these people to death," he said.

But Edwards' tone might have run too hot for the taste of some voters, even those feeling anxious about the economy.

While a forceful populist message has worked at times — as in Democrat Sherrod Brown's successful Senate race in Ohio against incumbent Republican Mike DeWine in 2006 — Americans are generally reluctant to embrace anti-corporate messages, Holzer said. Similarly, he said, many people are uneasy with attempts to rein in free trade and place new constraints on the rich, as Edwards suggested.

Clinton, by contrast, has portrayed herself as empathetic with those with economic fears rather than angry over their situation. She talks of a "trap-door economy" in which families are one layoff away from falling through the floor, but she generally has avoided the broad, anti-corporate language that Edwards adopted.

Surveys of voters in early primary and caucus states showed Edwards, despite his specific message, never found a niche.

In New Hampshire, he finished third among lower-income voters, taking 16 percent of those earning less than $50,000 a year, according to media exit polls. But he won 17 percent of those voters making more than $50,000. He won 11 percent of voters without high school diplomas and 18 percent of college graduates.

In the Iowa caucuses, he lost handily to Obama and Clinton among voters with annual household incomes of less than $50,000 but took a quarter of those in households earning more than $50,000, beating Clinton in that category.

And a new Los Angeles Times/CNN survey of California Democrats, taken before Edwards dropped out, showed him performing far better among upper-income voters than lower-income voters.

Still, campaign strategists believe Edwards retains power should he choose to make an endorsement.

Also, he controls 26 delegates to the party's national convention, and he has not said whether he plans to release them.

He said Wednesday in New Orleans that he dropped out only after receiving assurances from Clinton and Obama that they would make poverty a central theme of their campaigns and, if elected, their presidency.

Alluding gently to the fact his departure assures a nominee who is not a white man, Edwards said he was stepping aside "so that history can blaze its path."

But he also offered a critique of his own party for what he said was a lack of focus on the poor. "I don't know how it started," he said. "I don't know when our party began to turn away from the cause of working people, from the fathers who were working three jobs literally just to pay the rent, mothers sending their kids to bed wrapped up in their clothes and in coats because they couldn't afford to pay for heat."