It's Wisconsin or bust for Howard Dean (search), the Democratic presidential hopeful told supporters in an e-mail on Thursday.

The pre-Iowa front-runner turned underdog said Wisconsin, which holds its primaries on Feb. 17, is the "true test" of his campaign as he tries to get it back on track in the race for his party's nomination.

"The entire race has come down to this: We must win Wisconsin," Dean wrote to supporters, saying he needed to raise $700,000 by Sunday to launch a new television advertisement on Monday in major markets there.

"A win there will carry us to the big states of March 2 — and narrow the field to two candidates. Anything less will put us out of this race."

Asked if Dean plans to drop out of the race altogether if he loses in Wisconsin, Dean spokesman Jay Carson said, "It's a moot point because we are going to win Wisconsin. This is an e-mail to supporters to let them know how important Wisconsin is to the campaign."

Campaigning in Michigan Thursday, Dean wouldn't comment on the e-mail.

"All I can say is, we intend to win Wisconsin," he said. "We're raising a lot of money right now for the push in Wisconsin."

Dean and other rivals of Democratic presidential front-runner John Kerry (search) are fanning across the country in an attempt to garner enough support to close the gap between them and the seven-state winner.

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Wesley Clark (search) and John Edwards (search) skipped campaigning for this weekend's contests in Michigan, Maine and Washington state in order to focus on Virginia and Tennessee, two states that vote on Tuesday and where both candidates have southern roots.

Clark takes a bus tour of Tennessee while Edwards will travel from Memphis to Virginia.

Meanwhile, President Bush visited South Carolina on Thursday. Although the White House said politics had nothing to do with the trip, many Bush aides fear Edwards could give Bush a strong challenge in the backbone of Bush's support, the South.

Michigan and Washington state hold caucuses on Saturday, and Maine comes a day later for a total of 230 pledged delegates. Clark and Edwards do not plan to visit those states. Their strategists, focused on Tuesday's must-win Southern races, believe that Kerry will dominate the weekend contests.

Dean, the former governor of Vermont, plans to campaign in Michigan, but has acknowledged that he probably can't win there in Saturday's caucuses. He just hopes to pick up enough delegates to keep him in the race.

Edwards and Clark decided to air ads in Wisconsin, Virginia and Tennessee. Kerry will air ads in Tennessee, Virginia and the District of Columbia. Kerry opted not to advertise in the weekend states, though he will travel to them.

All the candidates are pointing to a Wisconsin showdown but the odds are with Kerry.

"Without money, you can't have the troops. Without troops, you can't compete. How can you compete with a guy who can write himself a check for ads in California?" said Michigan pollster Ed Sarpolus.

On the Campaign Trail

Edwards on Thursday claimed that trade agreements had eliminated jobs for working-class Americans.

"If George Bush and others who support free trade think everything is fine, then all they have to do is visit Morrison, Tennessee, and talk to the 1,300 people who just learned that the Carrier plant is going to shut down," Edwards said in remarks prepared for an event at Tennessee State University. "It is time we took the high road when it comes to trade."

Edwards has been trying to draw distinctions between himself and Kerry, who voted for the 1993 North American Free Trade Agreement that eliminated trade barriers with Mexico and Canada. Edwards was not in the Senate at the time, but he has said he would have voted against the pact.

He planned a trip later Thursday to Roanoke, Va., to attend a rally kicking off a two-day jaunt of Tennessee and Virginia, dubbed the "Strengthening American Jobs" tour.

Kerry has picked up the endorsement of Maine Gov. John Baldacci, former Senate majority leader George Mitchell of Maine, Michigan Gov. Jennifer Granholm, and Sens. Carl Levin and Debbie Stabenow of Michigan. "Senator Kerry is ready to lead. He is ready to take our country in a better direction," Baldacci said in a statement.

At a campaign event in Maine, a heckler shouted to Kerry, "Why don't you tell them about your vote on the war and the Patriot Act?"

Kerry has faced criticism from some Democratic voters and rival Dean for his vote in favor of President Bush's Iraq war resolution and his support of the Patriot Act.

"I'll explain them all as we go along," Kerry swiftly replied. "I never run away from anything, especially George Bush."

Then he pointed to a basketball net in the Boys' and Girls' Club gymnasium and read words stenciled on the backboard. "A winner never quits and a quitter never wins," he said, calling that an apt summary of his makeup.

Clark, meanwhile, sought on Thursday to clarify his comments from a day earlier in which he told a Tennessee voter, "I don't believe in abortion."

"I would hope that it would be done only on rare occasions, but it's a woman's right to choose. It's a private matter and I support the Supreme Court. I support Roe v. Wade. And I support a woman's right to choose," Clark told reporters as he campaigned in the state.

Gearing Up for 'Super Tuesday'

Clark, Edwards and Dean hope to rise out of Wisconsin as the only alternative to Kerry when the race turns to contests in California, New York and eight other "Super Tuesday" states March 2.

Two officials close to Clark said the retired Army general considered dropping out of the race Tuesday night after scoring an unofficial single victory, a nail-biter in Oklahoma. They said his wife, Gert, helped talk him into staying in the race against the advice of some backers.

Clark's staff also agreed to a pay freeze to pay for television ads.

The hopes of Edwards, Clark and Dean hinged on Kerry's future performance on the campaign trail and his past.

Dean suggested that "it'll be more of the same" if Kerry replaces Bush in the White House. Clark criticized both Kerry and Edwards, faulting them for complaining about White House policies that they had backed in the Senate.

In Michigan, where 128 delegates are at stake, polls show Kerry ahead by more than 40 percentage points.

Dean's strategists hold out a glimmer of hope because Washington has a history of backing underdogs and Maine has a small, unpredictable Democratic voting base. The state's 78 pledged delegates to the Democratic National Convention are at stake — the largest bloc since voting began last month in Iowa.

"We are going to win the Washington caucuses," Dean said on Wednesday. "Washington state will be the turning point, if we win, of this campaign."

The land of Microsoft and anti-war protesters in Washington seems tailor-made for Dean, whose Internet-driven campaign and opposition to the Iraq war vaulted him to the front of the Democratic pack. Dean raised nearly $680,000 there last year, more than most of his rivals combined.

"We're known for our edgy liberalism," said state Democratic Chairman Paul Berendt, who backs Dean. "Washington loves the maverick."

The Associated Press contributed to this report.