Their rivalry engaged, Democratic presidential contenders John Kerry and John Edwards unveiled distinctive strategies Wednesday for a 10-state showdown March 2. The challenger will attack Kerry’s free-trade policies and special interest ties, targeting Ohio, New York and Georgia.

The front-runner will battle Edwards on one front and President Bush on another, airing TV ads in general election battleground states while counting on arcane Democratic Party rules to protect his lead in nomination delegates.

“Every race is going to be contested. Every race,” Kerry said in Ohio, the focal point of his plans to beat Edwards in March and Bush in November. “We’re fighting for every vote.”

The rhetoric reflected a get-tough attitude in Kerry’s camp, victorious in the Wisconsin primary Tuesday but nonetheless stung by Edwards’ closer-than-expected second-place finish.

Kerry, winner in 15 of 17 contests and still the undisputed front-runner, failed to push his chief rival from the race. He settled for the departure of Howard Dean, the former Vermont governor who quit Wednesday after failing to win a single contest.

The Democratic race makes a pit stop next week in Hawaii, Idaho and Utah — where just 61 delegates are at stake — before turning to March 2 and the motherlode of 1,151 delegates, more than half the total needed to claim the nomination.

In Wisconsin, Edwards’ debate performance Sunday and his criticism of Kerry’s free-trade policies fueled his 11th-hour upswing. The first-term senator assailed Kerry’s 1993 vote for the North American Free Trade Agreement and also aired an ad condemning the treaty, without mentioning Kerry’s name.

Kerry also took a hit from Bush’s re-election team.

Kerry punched back on Edwards’ trade criticisms Wednesday after allowing them to go unanswered in Wisconsin.

Presidential hopeful U.S. Sen. John Kerry, D-Mass., makes a campaign stop at the Plumbers and Pipe Fitters Hall in Columbus, Ohio. Kerry and John Edwards are mapping different paths to garner delegates in 10 state primaries on March 2.

“He wasn’t in the Senate back then,” Kerry said in Ohio, coolly alluding to Edwards’ relative lack of experience. “I don’t know where he registered his vote, but it wasn’t in the Senate.”

The 19-year Senate veteran said he and Edwards have similar trade records, a reference to the North Carolina senator’s support for a China trade deal.

Edwards, a trial lawyer who shines in debates, may demand a series of one-on-one forums with Kerry, aides said. On Wednesday, he chastised Kerry for accepting donations from lobbyists. “Records matter,” he told reporters.

Strategists said trade could be a make-or-break issue in Ohio, a state narrowly won by Bush in 2000 but among the hardest hit by job losses.

Greg Haas, a Democratic strategist in Ohio, said Kerry holds the advantage because of his winning streak.

“But NAFTA could pay dividends for Edwards here,” said Haas, an adviser to Columbus Mayor Michael Coleman. “He wouldn’t need any ads — just saying the word NAFTA in northeast Ohio is like raising a red cape in the face of a bull.”