Once thought to have a frosty relationship, John F. Kerry and John Edwards cannot seem to get enough of each other.

In their first week as the Democratic Party's prospective 2004 ticket, they have hugged and patted, playfully ruffled each other's hair, reveled in their wives and families, tossed a football -- "I'm a receiver," Edwards said -- and traded advice on topics such as how to handle reporters' questions and how they can defeat President Bush and Vice President Cheney in November.

They arrived in Edwards's home state on Saturday afternoon to a throng of cheering supporters at an outdoor rally on the campus of North Carolina State University. It was the last stop of their journey this week and one that emphasized the remarkable arc in the career of the North Carolina senator, who six years ago was making his first run for public office and who now seeks the second-highest office in the country.

"I'll tell you something, when we bring friends back to North Carolina to see our friends, to see our families, to introduce, we always say, 'He's with me,' " Edwards told a crowd estimated at more than 20,000. "I came here to tell you that this man right here, I am with him."

Edwards's addition to the ticket has produced what Kerry advisers had hoped, which is an infusion of energy and enthusiasm to a Democratic Party already united in its determination to make Bush a one-term president. From Ohio to Florida to West Virginia to New Mexico, crowds in battleground states greeting Kerry and Edwards have been large, responsive and obviously upbeat about the running mate.

Even more obvious has been the impact on Kerry, a reserved and sometimes stiff campaigner. The Massachusetts senator appears more buoyant and, in the estimation of his advisers, more positive in his campaign style with his ever-smiling running mate on the stage with him.

"Clearly Kerry's a lot looser than he was a few weeks ago," said one adviser, who declined to speak on the record about internal campaign observations.

Another Kerry adviser said: "Kerry clearly enjoys having a partner in the fight that he's been carrying on for two years. Having somebody at his side has been a huge amount of relief for him."

The Kerry campaign has captured Edwards's advocacy in a new ad released Saturday that will begin airing here and in battleground states around the country. In it, Edwards says the support Kerry has from the men with whom he served in Vietnam is testimony to his character and his suitability to serve as president.

Edwards, who demonstrated his campaign skills during the primaries, appears to revel in his new role. After indicating to aides that he wanted to rest after a Friday night rally in Albuquerque, he was knocking on the door of a senior adviser late in the evening, still wanting to talk.

Edwards worked hard to make himself Kerry's running mate, and it was clear from a comment by his wife, Elizabeth, at the Albuquerque rally how much he and she wanted the chance to run with Kerry. Paying tribute to New Mexico Gov. Bill Richardson (D), who was once seen as a possible running mate for Kerry, she said, "We have to admit that a few days before this selection process, Governor Richardson graciously took himself out, and we went, 'Whew!' "

During the primaries, Kerry questioned Edwards's readiness to be president, and Edwards questioned whether the four-term senator could put a forward-looking face on the Democratic Party. Now, in the words of one adviser, "They've taken on roles with one another as defender, supporter and friend."

Teresa Heinz Kerry, in her introductions this week, called the new duo the "Johnnys B. Goode," and the old Chuck Berry classic blares from the sound system at Kerry-Edwards rallies. One Kerry adviser noted that the feel-good mood had begun to reshape Kerry's stump speech, which on Friday and Saturday did not mention the president by name. Instead, he talked about his own agenda for the future.

"The message of optimism has jelled with the two of them," the adviser said.

Republicans have a different view, having dubbed Kerry the candidate of pessimism and misery, and the Democratic duo hit a speed bump Thursday night in New York, when a Democratic Party fundraising concert turned into what Bush-Cheney campaign manager Ken Mehlman called "a star-studded hate fest" aimed at the president -- and where comedian Whoopi Goldberg repeatedly referred to Edwards as "kid."

Kerry and Edwards tried to distance themselves from the strongest remarks, but Republicans said the concert reflected the real Democratic Party.

Edwards's role and travel plans are still evolving. He will begin his first solo campaign trip next week. Advisers said the itinerary tentatively includes Arizona, California, Florida, Illinois, Iowa, Louisiana, North Carolina and Texas. The stops in California, Illinois and Texas are largely for fundraising.

Some Democrats say the addition of Edwards puts more of the South into play against Bush, but one campaign adviser sounded cautious about how much time Edwards will spend there. "I don't think we're going to get cocky here," the adviser said.

Edwards also is getting used to a new staff. Having built a presidential campaign operation over the past two years, he inherited a Kerry-made team on Tuesday morning. Some Democrats said the absence of his former team was initially unnerving, but Kerry advisers said the integration is going smoothly.

Republicans respect Edwards's talents as a campaigner, but they say the first-term senator is no match for the vice president in terms of experience and understanding of the world. Kerry advisers said Saturday they welcome the coming comparisons.

"The Bush campaign sees the differences between Cheney and Edwards as a plus for them," one adviser said. "We also see it as a plus for us. You can't have more contrasting vice presidential roles, and we're pretty happy with the way ours has come together."