Opening his latest presidential campaign swing through Iowa, Democrat Barack Obama singled out rival John Edwards for criticism, arguing that the former North Carolina senator doesn't have a track record to back up the sharply populist themes he sounds on the campaign trail. "I've got a track record," said Obama. "I don't just talk the talk, I walk the walk. John does not have the same track record." The Illinois senator and his aides also singled out a new television campaign they said is being launched on Edwards' behalf, accusing him of hypocrisy.

"John said yesterday, he didn't believe in these 527s, those are these independent groups that raise money with no disclosure, nobody knows who is giving them, he said I don't believe in them," said Obama. "We found out today there's a group buying three-quarters of a million dollars worth of television and the individual running the group used to be John Edwards' campaign manager."

Obama used the occasion to suggest that Edwards is guilty of hypocrisy.

"You can't say yesterday, you don't believe in it and today three-quarters of a million dollars is being spent for you," said Obama. "You can't just talk the talk. Everybody talks change, but how did they act when it was not convenient, when it's hard."

Campaign aides distributed to reporters a list of television ad buys in six markets covering Iowa totaling $796,610 that were purchased by the Alliance for a New America, which they described a pro-Edwards group. Focusing on Edwards could signal that Obama views him as a greater threat than previously perceived.

Edwards has generally slightly lagged behind Obama and New York Sen. Hillary Rodham Clinton in polls of likely Democratic caucus-goers in Iowa, although the three-way race is considered tight.

Obama also extended his criticism to Edwards' single term in the Senate.

"During six years in the Senate he wasn't passing laws to reduce the power of lobbyists," said Obama. He contrasted that with his own role in crafting new ethics legislation.

Obama was spending his day seeking to focus on trade policy, an issue Edwards has strongly emphasized.

On the stump and in new television commercials, Obama called for more training and health coverage for workers who find their jobs shipped overseas as well as giving them significantly more time to find another job.

"We're not going to stop globalization in its track, but what we can do is have a president who's standing up for American farmers and workers," said Obama, speaking to about 300 people in a middle school gymnasium.

Obama also began airing a new commercial in Iowa titled "Enough" in which he uses the 30-second spot to vow to end tax breaks for companies shipping jobs overseas, giving them instead "to companies that are investing right here in Iowa."

As the voting season nears, there are signs that voters are beginning to focus on pocketbook economic issues and Obama was responding by seeking to capitalize on the frustration and anger many feel as they watch companies move overseas, leaving workers high and dry.

"When I'm president we'll give you training before you lose your job if there's a good chance it will get shipped overseas," said Obama. "We'll give you an education account that you can use to retrain."

Also, Obama vowed financial aid for workers who find themselves displaced.

"We'll help ensure that losing your job doesn't also mean losing health care by giving you some extra money to pay for it," said Obama. "And we'll make sure employers give you an extra month's notice before letting you go - so you have 90 days notice instead of just 60."

Obama said he's formulated his economic policy by holding round table meetings with small groups of voters around the state, where he hears stories of working families.

"People are working harder and harder just to keep pace," said Obama. "People have lost faith that their leaders can or will do anything about it."

Written By MIKE GLOVER