For a politician whose stock was built on sunny optimism, Sen. John Edwards is serving up plenty of bare-knuckled rhetoric on the campaign trail these days.

There was, for example, his assessment of the Bush administration's foreign policy prowess, offered at a raucous rally here Wednesday.

"The truth of the matter is, Iraq is a mess because this president and this vice president were incompetent," Sen. John F. Kerry's running mate told a largely blue-collar crowd. "They were incompetent in building a coalition. They were incompetent in having a plan. . . . If you want to know how successful this president and vice president will be on the war on terror, all you gotta do is look at their incompetence on Iraq."

Edwards said the word "incompetent" seven times in the first seven minutes of the speech.

Here, and in other battleground states in recent days, Edwards also has said that President Bush's "incompetence" extends to other areas, including his reaction to the shortage of flu vaccine. "When I talk about his incompetence, it runs across the board," Edwards said earlier this week in Windham, N.H. There, he also mocked Bush for a "solution" to the vaccine shortage that he offered during a presidential debate: not getting a shot himself.

Such sharply worded attacks have become standard for vice presidential candidates, who often put matters more bluntly than the candidate on top of the ticket.

But there were questions about whether Edwards would play that role when Kerry picked him as his running mate in July. During his presidential bid, the energetic senator from North Carolina found his niche in a crowded Democratic field by touting the virtues of forward-looking solutions and staying positive.

This summer, as Kerry's poll numbers sagged, some Democrats -- inside and outside the campaign -- grumbled that Edwards was not being aggressive enough in roughing up the Republicans. Republicans now suggest Edwards's tone reflects a campaign in trouble.

Aides to Edwards acknowledge the talk is tougher but say it has been motivated neither by concerns of Democrats nor by fear of falling behind the GOP ticket. The reality, they suggest, is more nuanced.

Immediately after joining the ticket, Edwards's message focused by design on promoting Kerry. Edwards's task was to boast about Kerry's military service and character in a way that might have been unseemly if Kerry did it himself.

Kerry has now been better defined by the Democratic convention and, especially, the presidential debates, so Edwards, a former trial lawyer, is free to place more emphasis on what aides have dubbed the "indictment" of Bush.

The case includes rhetoric offered here in Canton asserting that Bush has catered far more to special interests than to the American people. "Over and over George Bush has made clear which side he's on," Edwards said. "You cannot be with big drug companies, big insurance companies, big HMOs, Halliburton, big oil and the Saudi royal family and still be with the American people."

Edwards's speech still includes uplifting riffs. He often closes by repeatedly proclaiming "Hope is on the way," as he did in his Democratic convention speech.

But, in some respects, Edwards's reputation for staying positive may exceed the reality of his record.

In a May 2003 debate in Columbia, S.C., early in the Democratic presidential race -- in a harbinger of his current attacks on Bush -- Edwards blasted a rival's health care plan, which relied heavily on providing tax subsidies to employers. "It feels like saying, 'You're in good hands with Enron,' " Edwards pointedly told Rep. Richard A. Gephardt (Mo.).

It was not until several months later that Edwards started incorporating his pledge not to attack Democratic rivals into his stump speech. His stance distinguished him from some of his rivals, including Gephardt and former Vermont governor Howard Dean, who clashed repeatedly.

Occasionally Edwards released himself from his vow, including in his final debate before dropping out, in which he said Kerry offered "the same old Washington talk that people have been listening to for decades" on issues such as trade and deficit spending.

And Edwards never really refrained from attacking Bush -- sometimes in tough, personal language. In several stops before the Iowa caucuses, he called the president "a phony."

The more sustained attacks now do not seem to hurt Edwards's good-guy image with Democrats who turn out for his rallies.

"There's a lot of tough rhetoric," said Sue Centner, executive director of a nonprofit teen safety group, who turned out to see Edwards in New Hampshire, "but he's young, passionate and bright, and all those qualities project optimism."

Vice presidential nominee John Edwards has been pointed in his criticisms of President Bush, especially his foreign policy record.