Republicans also say they're delighted with Kerry's selection, claiming that Edwards will be a ripe target in the next four months.
On Saturday, just as the candidates concluded a four-day marathon tour of battleground states, Correspondent Lesley Stahl sat down with Kerry and Edwards – and a bit later, their wives, for their first joint television interview.
Kerry tells Stahl that Edwards, his pick for his vice presidential running mate, is "spectacular."
Is some of Edwards' energy rubbing off on him? "Well, I certainly hope so. I want it to. I love it," says Kerry.
"But he's definitely got energy without me, you know," adds Edwards. "You don't have to be a rocket scientist to see a number of things. One is that we like each other. Two is that we we're having a great time on the campaign trail. And three is we're good for each other."
Is the Democratic presidential candidate worried about being upstaged by his running mate?
"I could care less," says Kerry. "Look, this is about issues. It's about Americans; it's about problems. If he does a great job of going out, which I know he will, this is why I chose him - because I wanted the best person and I think he's the best."
Does Kerry think Edwards is a better campaigner? "No. I think I'm pretty darn good," says Kerry, laughing. "But you know what, so is he. He's fabulous."
Kerry said the two candidates had a talk before agreeing to be running mates. "We talked about his vision of the role, my vision of the role, and it was finding that comfort level that's important in any kind of relationship," he says.
"I found it. I think the best modern example frankly is Al Gore and Bill Clinton. But I think it could be taken even further. And we hope to do that. It's a full partnership."
Is he worried about Edwards' ambition? "It's not a question of ambition. I want ambition. I think ambition is good," says Kerry. "Al Gore wanted to be president. But President Clinton knew Al Gore wanted to be president."
Edwards says he didn't need to ask for any assurances about being involved in policy decisions: "At the end of the day, all the words in the world will not make up for one thing – we have to have trust. I trust him."
This is quite a switch for two politicians who reportedly didn't like each other much – and were rivals for the Democratic nomination just a few months ago.
"We've been on the road, competing with each other in 30 some odd forms of presidential debates," says Edwards. "We know each other very, very well."
Both candidates deny that they attacked each other a lot on the campaign trail. "That's not true," says Edwards. "I would not agree with that."
"There was never any bad blood. I'll absolutely tell you, in fact, the one time I said something I thought was really silly and over the top," says Kerry, referring to a comment he made at a press event that he wasn't sure if Edwards was "out of diapers" when he came back from Vietnam in 1969.
Edwards said that Kerry contacted him immediately after making that statement. Kerry adds: "I was on the phone with John within the hour. And I said, 'John, you know, I said something stupid,' and we talked about it and it was gone."
Now, it's the Republicans who are making the charge that John Edwards doesn't have enough experience.
When Stahl asked both candidates how Edwards measures up to Vice President Dick Cheney in terms of presidential experience, Edwards said he was "absolutely prepared to be president."
"I have a vision for this country which is consistent and completely compatible with John's [Kerry] vision," says Edwards.
"I've seen people be president. I've worked with presidents. I understand talent and ability," adds Kerry. "I also know that this man is eight years older than Jack Kennedy was when he became president of the United States. He is more qualified, more prepared in national affairs and national issues than George Bush was when he became president. He is ready. And I chose him because he's ready."
So how does Edwards plan to handle Cheney in a debate? He says he's going to be himself.
"For 51 years, I've been myself and it's worked pretty well," says Edwards, who adds that he's going to be polite and tough. "I'll be tough because there's so much at stake for this country. The voters of America need to know what the differences are between us."
The Republicans have done everything in their power to portray Kerry as a serial flip-flopper on issues. How damaging has that been to his candidacy?
"Well, it's just not true," says Kerry. "I mean, if you spend $85-90 million, then a few people may believe one thing or another."
But it was Kerry himself who handed Republicans their best ammunition for a TV ad when he talked about voting against the Iraq Reconstruction Bill. When asked about this issue, Edwards defended his running mate.
"No. 1, you've been president of the United States for four years. You've spent $80, 90, 100 million on television - almost all of it talking about your not-yet-nominated opponent? What does that say about your administration and its accomplishments," says Edwards.
"Second, flip-flopper? You gotta be kidding me. I mean, a guy who put his life on the line for the men who served with him in Vietnam every day? Ask them what he's made of. Ask them what kind of backbone and courage he has."
Is Kerry for or against the war in Iraq? "I think the president made a mistake in the way he took us to war," says Kerry. "I am against the war - the way the president went to war was wrong."
The Senate Intelligence Committee has just issued a report saying that the basis for the war was erroneous, and that there weren't weapons of mass destruction. Given what he knows now about that report, would Kerry have made the same decision?
"What I voted for was an authority for the president to go to war as a last resort if Saddam Hussein did not disarm and we needed to go to war," says Kerry. "I think the way he went to war was a mistake."
"I know you want to make this black and white, but the difference is - if John Kerry were president of the United States, we would never be in this place," adds Edwards. "He would never have done what George Bush did. He would have done the hard work to build the alliances and the support system."
"Why build an alliance if they didn't have weapons of mass destruction," asks Stahl.
"We would have found out, that's the point," says Edwards.
Regardless, Kerry says he doesn't regret his vote: "I believe, based on the information we have, it was the correct vote."
Edwards has said that if he is elected "no young Americans will go to war needlessly."
"That's true," says Edwards. "He [President Bush] didn't do the things that should have been done before taking this country to war. This is not a – I mean, we've now said it 10 times, this is not a complicated thing."
Ron Reagan Jr. was recently very critical of President Bush invoking religion when it comes to policy – particularly in the war in Iraq. What do the candidates think of this?
"Abraham Lincoln wisely avoided trying to invoke God on the side of the North or assist the South, but prayed that he was on God's side. I think that that's the lesson that John and I would bring to this. We are both people of deep faith," says Kerry.
"I think that and I respect the president's faith. I don't question it. None of us do. But I think it's important for us to be really mindful of not stepping over that precious line that the founding fathers drew. And I believe that on a number of occasions this president has stepped over that line," says Kerry.
Edwards adds: "It is not the job of the president of the United States to decide what the religion of America is or what the religion of the world should be."
Kerry, a Massachusetts Catholic, and Edwards, a North Carolina Methodist, have spent the last four days barnstorming seven battleground states.
But it's not just the two Johns who've been thrown into the campaign cauldron -- where every word, every gesture, is a potential target for the opposition. It's their families, too.
At the Edwards home in North Carolina, Elizabeth Edwards and Teresa Heinz Kerry sat down with 60 Minutes on Saturday for their first interview together.
How is the honeymoon going?
"I think we need to start looking for Silver Anniversary gifts. This is a marriage that's working," says Elizabeth Edwards.
"We're just getting to know you," adds Teresa Heinz Kerry, referring to the song from the musical, "The King And I." "No, we're what? Four days in? And all we've done is laugh and have a good time."
What are they laughing about? "You know what it is, when you're happy and when you feel good chemistry, and you're at ease with yourself and those around you, and have good energy and all that, you laugh," says Teresa Heinz Kerry. "It feels good. It's therapeutic and it's happy."
She makes it sound like they're on a double date -- not in the midst of a campaign where charges and counter-charges are flying back and forth every day.
"One of the Republican attack lines is that you all are all mega-millionaires who are running on economic populism," says Stahl to the candidates and their wives.
"Is this coming from millionaire George Bush? And millionaire Dick Cheney? And millionaire Rumsfeld? And all the rest," says Kerry. "This is the most ridiculous thing I've ever heard in my life."
"Can I say something? First of all, those very same people never criticized my late husband for his money or his wealth. In fact, they used it - and his money was just dandy," says Teresa Heinz Kerry.
"Secondly, I find it un-American for people to criticize someone and say they're not deserved for any position whether because they have too much or too little, or because they're black or they're white. That's un-American."
"I just want to say one thing and this is that these two men voted against tax cuts that would have benefited them," adds Elizabeth Edwards.
"Isn't that what we want? A leader who looks at the greater good instead of what simply what benefits the people himself, or the people in his own class for their donors or whatever else you're looking at? These men did what was right for all Americans and it seems to me that's an enormous test of character -- whether you're willing to step out and do something against your own self interest."
Stahl then asked Teresa Heinz Kerry why she called the Democratic running mates "The Johnnys Be Good," at a rally Saturday in Raleigh, N.C.
"That's a song, 'Oh, Johnny Be Good,' and they will be good if Elizabeth and I have anything to do with it," says Teresa Heinz Kerry, who adds that it's also important for them to keep their husbands honest.
"Honest means keep true to yourself, because there's so many people around anyone in power that inflate their egos, or try to destroy them for that matter. And I think it's the person that knows them best that has to stand by them and keep them whole. Sometimes it's to keep the ego down, sometimes it's to bolster it up, but that's what a good spouse has to do."
"You know, when an aide leaves the room after telling him he was terrific, to say that, you know, that really wasn't actually your best job you ever did," adds Elizabeth Edwards. "Or, if you're talking about things the Republicans might say, somebody says something and you say, 'Don't give it a second thought.'"
"It's a very healthy thing to have somebody that is the love of your life, that you trust as your life partner to say that to you," says Edwards. "It's a very good thing."
Stahl then asks Teresa Heinz Kerry how she can "take all of the jokes about Sen. Kerry's charisma" – or lack of it.
"He is not a funny Irishman. You know? That's not who he is," says Teresa Heinz Kerry. "I was married before to a wonderful guy who also didn't have that kind of sense of humor. You can't pretend to be what you're not. That doesn't mean that you're not a good person or competent. He is who he is."
"Well, he had enough charisma to get this incredible woman to marry him, so he can't be completely out of charisma," adds Elizabeth Edwards.
Kerry, however, says he's sort of amused by it all.
"I don't worry about it very much. I don't really worry about it. You know, I remember when people wrote about John Kerry's charisma," says Kerry. "I mean, I got elected four times. I won the nomination. … So there."