John Edwards (searchsaid Thursday he'll keep his presidential campaign tightly focused on a positive message -- not to win a spot on the Democratic ticket, but because attack politics simply don't work any longer.

Although he's won only once in 14 delegate elections and is struggling to raise money, Edwards is pressing forward amid speculation he's in search of the No. 2 spot on the ticket. Some argue his positive campaign is designed to avoid offending the front-running campaign of John Kerry (search).

Edwards said he is in a two-man race with Kerry now that Wesley Clark (search) has dropped out and Howard Dean (searchhas faded. But polls show Edwards trailing badly in next week's Wisconsin primary, and the big boost in support he expects with Clark out may be blunted if his fellow Southerner endorses Kerry.

Clark plans to endorse Kerry on Friday.

Edwards said he will continue to seek the nomination regardless of his showing in Wisconsin. In an interview with The Associated Press, he noted that half the original Democratic field has dropped from the race, largely candidates who sought to attack their opponents.

"The reason I broke through in Iowa in the last couple of weeks is because the positive message finally broke through," he said. "The same thing happened in South Carolina, where a couple of weeks before that I was behind. We surged ahead."

Stumping in Wisconsin, Edwards hammers hard at trade policies he says have drained thousands of jobs from the nations economy. It's an important issue in Wisconsin, where 74,000 industrial jobs have been lost since President Bush took office.

"The truth is we have seen a sea change in the middle class in this country in the last 20 years," he said. "We have to have a president who will fight for jobs. People are desperate for someone who will protect their jobs and fight for jobs."

Edwards is mixing daily campaign events in Wisconsin with side trips to other states. After appearing at a community center, he was flying to California for a fund-raiser and a campaign event near Los Angeles, returning late in the evening to Wisconsin.

Edwards will repeat that swing on Friday, stumping in Milwaukee before heading back to California to raise money and appear on NBC's "Tonight Show with Jay Leno."

Although he has won only once -- in South Carolina, the state where he was born -- Edwards contends he is the most electable Democrat.

"We have to have a candidate who can appeal across party lines and who can appeal to independent voters," he said. "I have a proven history of doing that."