"The one thing you can count on is you will never see a picture of me on the front of Fortune magazine saying I am the candidate that big, corporate America is betting on," he said, an unmistakable reference to a cover story about Clinton with the headline "Business Loves Hillary! (Who Knew?)"
On his current bus tour of Iowa, with the caucuses only three weeks away, Edwards rarely mentions his rivals. His campaign believes he hardly needs to because he spent months branding them - Clinton as the corporate Democrat,as the callow compromiser who would negotiate with special interests.
On the campaign trail, his antagonists now are the corporations and special interests themselves. The Clinton and Obama references are merely implied, hidden in a populist message he calls "America Rising." For the former trial lawyer, it's a closing argument to break away from a virtual three-way tie in Iowa and rise above the fray engulfing his main opponents.
"The reason we don't have universal health care is the insurance companies, drug companies and their lobbyists in Washington," he said in Grinnell, Iowa, this week, repeating a line in his standard speech.
The unspoken message: Clinton tried to overhaul health care as first lady and failed; Clinton accepts political contributions from lobbyists.
"Some people suggest, 'Oh, we'll be able to sit at the table with drug companies and oil companies and they're going to give their power away? Right," he said sarcastically at another point. "It will never happen. I'll tell you when they'll lose their power, when we take it away from them. That's when they'll lose their power."
That's the unmentioned Obama. The message? He's too accommodating.
Asked why Clinton and Obama critical lines are now missing from his repertoire, Edwards told The Associated Press: "My focus for these last few weeks is on a positive agenda. That's what 'America rising' is all about."
Merely not being Clinton seems to be enough for some Iowans.
"She changes her opinions from one day to the next," said Ellen Ballas, a college project coordinator who caucused for Howard Dean in 2004. She said she would caucus for Edwards this time.
"Since he began his campaign he has been concise in calling out the neocons and calling Hillary a corporate Democrat, which is exactly what she is. I think we're going to get more of the same from her as we did with Bush."
It is not a bad time for Edwards.
Clinton and Obama are caught in almost daily spats. Public and internal polls show Edwards has the biggest support from the most reliable caucus-goers - those who have attended the caucuses before. A CNN poll this week showed he's the Democrat who can most soundly beat any of the leading Republican candidates.
"For him to be in a position where it's a jump ball with three weeks to go is particularly important for Edwards because he hasn't had the same level of high-profile surrogates and he has not been spending the kind of money that Clinton and Obama have," said Jeff Link, a former Edwards adviser who is now assisting independent efforts on Edwards' behalf, including the Iowa Service Employees International Union.
Indeed, Obama has spent more than $6 million in advertising in the state. Clinton has spent about $5 million. But Edwards has begun to catch up, airing about $1 million in ads during the past two to three weeks - a level of spending on par with his rivals. His latest ad, released Friday, focuses on insurance and drug companies as well as lobbyists.
The stakes are high. A third-place finish in Iowa could be deadly for any of the three. Even second place may not be good enough. Edwards knows, he was a surprising second in 2004 but failed to turn that into momentum.
"What I know is that Senators Clinton and Obama have spent massive amounts of money in this state, far more than they've spent anywhere else and they believe that it's crucial to them," Edwards said in the AP interview. "And I think an honest assessment would be that it's important to all three of us."
Edwards told CBS News's The Early Show that he'll be prepared to capitalize on a good finish in Iowa thanks to strong organizations in later states.
"I'm in a dead heat here in Iowa where I feel strong, very strong in South Carolina, strong in New Hampshire," Edwards said. "I think we've got a great chance. But the most important thing is to focus on what we want to do for the country instead of just talking about politicians and polls."
Still, his advisers worry that Edwards needs to convince voters that he can indeed win the primary. And they also fret that the current Clinton-Obama fight could help Obama rather than end up in mutual destruction.
Steve Murphy, a media consultant who advised Dick Gephardt's presidential bid in 2004 and now works for Democrat Bill Richardson's campaign, said polls show Edwards has some of the highest favorable ratings among Iowans. But he said his image suffers if the contest looks like a two-way race.
He said Edwards would benefit from a smaller caucus turnout, which would indicate participation by seasoned caucus-goers who favor Edwards.
"When you get a bigger universe," he predicted, "you get a big Obama win."
And Edwards' 2004 support is not guaranteed to hold firm.
Sue Blaisdell of Marshalltown, Iowa, caucused for Edwards four years ago, but is a precinct captain for Clinton this time.
"The needs of the female part of the country, or the down-and-out part of the country, need to be better understood," Blaisdell said as she waited for Edwards at a town meeting this week. "Hillary, being more of a mother figure than all of the guys, can represent that better."
Edwards advisers believe a populist message can win in Iowa, much like it helped Gephardt win in the state in 1988. They've tested populist-sounding ads in New Hampshire and found that it helped Edwards significantly with independent voters, who can vote in that state's primary.
It's working with voters like Willis J. Knight, a retired school counselor from Iowa City who now works with at-risk families.
"He represents an attempt to reach the common people," Knight said. "The middle and lower class is getting left out."