"This is a huge moral issue facing the country," the former North Carolina senator told the Los Angeles Times as he began a Memorial Day swing through Iowa. "I don't see in polls that it is a driving issue (for voters), but it is for me."

For more than two years now, Edwards has been polishing his credentials by visiting with survivors of Hurricane Katrina, appearing at union rallies and shadowing low-wage workers as they go about their jobs.

"It is very brave to take on an issue that he himself says has no constituency that has power, but it's a tough road to be trodding to the White House," says Matt Bennett of the centrist Democratic research organization Third Way.

Analysts warn Edwards' populist strategy risks alienating middle-class swing voters and moderate Democrats who do not want the party to be viewed as catering only to the poor.