John Kerry (search) said Wednesday that Democratic rival John Edwards (search) has nothing on him on the issue of trade, a key concern for rust belt voters who blame overseas competition for the loss of manufacturing jobs.

Edwards gave Kerry a scare Tuesday in Wisconsin's primary after contrasting his opposition to the North American Free Trade Agreement (search) to Kerry's Senate vote for it in 1993. Edwards plans to continue the criticism as the two head toward upcoming nominating contests in Ohio, New York and Georgia.

But Kerry said he and Edwards have the same policy on trade. They both voted for normalized trade relations with China and both want to see labor and environmental standards addressed in trade pacts, he said.

Although Edwards said he would have voted against NAFTA (search), Kerry said: "He wasn't in the Senate back then. I don't know where he registered his vote, but it wasn't in the Senate."

Edwards said he opposed NAFTA in his 1998 Senate campaign. He said he's also voted against other trade deals that Kerry has supported, such as the Caribbean free trade agreement and granting the president "fast track" authority to negotiate international accords that Congress must approve but cannot change.

"As Senator Kerry himself has pointed out many times during this campaign, records matter," Edwards said. "I think there is a significant difference between us on this issue."

Asked later, in a conference call with reporters, to elaborate on those differences, Edwards mentioned "the fact that I don't take contributions from Washington lobbyists" and differences on "how we deal with the plight of the middle class."

Kerry spokeswoman Stephanie Cutter said he would continue to talk to voters about what he wants to do to change the country. "We're surprised that John Edwards has turned negative so quickly," she said.

Edwards said he's personally seen the effect of people losing their jobs, having grown up in a North Carolina mill town. Although Edwards doesn't mention Kerry's upbringing in boarding school and Boston society, there is a clear contrast.

Kerry said a person's roots should not be part of the debate, which should be about what they've done for people.

"If where you come from was a qualification for being president, we'd have never had Franklin Roosevelt or John Kennedy," he said.

While campaigning in Wisconsin, Kerry often faced questions about his support of free trade and the movement of jobs overseas. The trend continued in Ohio, which Kerry said has lost 160,000 manufacturing jobs since Bush took office.

A woman at a town hall meeting in Dayton said her husband works alongside employees imported from India who will work for a lower wage. Another man talked about his father and grandfather fighting in wars against communism, only to see American companies opening shop in communist countries. Another woman said "fair trade verses free trade" would make the biggest difference in the economy.

In Dayton and in Columbus, Kerry was applauded when he promised to review all trade agreements after taking office to check for worker and environmental protections.

"I pledge to you that we will have not just trade, but smart trade, fair trade, trade where we are giving the American worker a fair playing field to compete on," Kerry said at the Plumbers and Pipefitters Hall in Columbus.

With Dean out of the way, Edwards and Kerry will engage in a one-on-one contest for the 13 states that hold primaries and caucuses in the next two weeks, with particular focus on the 10 "Super Tuesday" states on March 2.

A supporter at a United Auto Workers hall in Dayton called out to Kerry, "Mr. President!" But Kerry cautioned that was premature.

"I've got to win this nomination first, and I'm counting on Ohio," he said.

Dean's exit from the race brings an end to perhaps the most heated rivalry in the Democratic campaign. From the beginning more than a year ago, Dean and Kerry have had a spirited competition marked by personal animosity.

Dean began by singling out Kerry's support for the Iraq war resolution for criticism. Kerry resented Dean's dominance in fund-raising and media coverage last year, and once left a press interview muttering, "Dean. Dean. Dean."

As Dean lost race after race to Kerry, the former Vermont governor stepped up his attacks, calling Kerry the "hand maiden of special interests," and, perhaps more insulting, a Republican.

Kerry said he doesn't hold a grudge for anything Dean said about him during the campaign. He said he has great respect for Dean's creativity in bringing disaffected voters back into politics.

"It's impossible not to express admiration and respect for the campaigning that he's put together and what he's achieved," Kerry said.

Kerry was headed to Washington on Thursday to pick up the endorsement of the AFL-CIO, and planned to spend Friday and Saturday meeting with advisers in Boston.