BOSTON — Congressional Democrats are preparing a full-blown campaign push on behalf of the Democratic presidential ticket over the coming weeks, as Sens. John Kerry (Mass.) and John Edwards (N.C.) barnstorm across the country in search of votes in battleground states.

Kerry and Edwards are visiting 21 states as part of their “Believe in America” tour that was launched Friday, just hours after the gavel fell on the 2004 Democratic National Convention.

Over the next three months, Congressional Democrats are expected to serve as surrogates in key states to counter what many of them anticipate will be a well-orchestrated GOP critique of Kerry’s ability to lead the country.

“I think the Republicans are going to unleash one of the most blistering, scalding series of negative ads ever in America’s political history in order to drag John Kerry down,” said Rep. Ed Markey (D-Mass.). But Markey, who serves as Kerry’s chief liaison in the House, said his fellow Massachusetts Democrats have been able to draw disparate factions of the party together with the common goal of defeating Bush in November.

“You can feel it,” Markey said. “There is an incredible unity. We are all passionately focused on getting him elected.”

As part of that effort, Minority Leader Nancy Pelosi (D-Calif.) has been talking to different segments of her Caucus — from women to conservatives to minority groups — in hopes of encouraging them to travel to key battleground states on behalf of the Kerry-Edwards ticket. She’s asked lawmakers to work on the ground both for Kerry and for Democratic candidates in close races.

“We want House Democrats to get out there,” said Pelosi spokesman Brendan Daly, while adding that Pelosi also wants Members to make sure they are able to campaign in their own districts. “The theme of our convention is unity. And we are united and focused on getting John Kerry and John Edwards elected and also electing a Democratic House,” he said.

House leaders are now working on the logistics for their travel plans, Daly said, adding, “We will fan out.”

“John Kerry said we are the eyes and ears down on the ground, and we understand local politics in our districts,” added another Democratic leadership aide. “Democrats are eager and willing to help to in any way we can.”

Congressional Democrats are also mapping out legislative game plans for when they return in September — a period that is expected to accentuate the partisan tone of the November elections.

Last week, Senate Democratic leaders called on Senate Majority Leader Bill Frist (R-Tenn.) to immediately approve a spending bill for homeland security as well as focus primarily on the remaining unresolved appropriations bills.

“Given the limited time remaining in this work session and the current security environment, we believe we no longer have the luxury of wasting precious Senate floor time on politically-charged proposals that are doomed to fail,” Senate Minority Leader Tom Daschle (D-S.D.) wrote Frist in a letter last week. “It is essential that you dedicate the next work period in its entirety to consideration of must-pass measures crucial to the American people.

“If we pursue the approach outlined below, we can pass important legislation in a bipartisan manner and demonstrate to the American people that the Senate can get things done in an election year,” Daschle continued in the letter that was also signed by Senate Minority Whip Harry Reid (D-Nev.) and Sen. Robert Byrd (D-W.Va.), the ranking member on the Appropriations Committee.

But Rep. James Clyburn (D-S.C.) said he believes that discussing politics within the context of the policy decisions Congress will have to make this year is unavoidable. He urged Democrats to highlight the differences between the two parties.

“Kerry and Edwards ought to ratchet things back up and have a national debate over the inactions of the administration,” Clyburn said.

The South Carolina Democrat also urged Kerry to conserve his campaign war chest until September, when both Kerry and Bush will likely be constrained by the same spending restraints.

“Hopefully, the [Democratic National Committee] and the other party apparatuses around the country will run the campaign for a while to keep our policies, keep our proposals and keep the platform out there,” Clyburn said.

Rep. Carolyn Maloney (D-N.Y.) warned Democrats not to bask for too long in the optimism that marked last week’s political rally in Boston.

“One danger I see is that everyone is so euphoric and so positive and feeling like we are winning,” she said. “In reality, we have a tremendous amount of work ahead of us — to get the votes out, to get people registered, to get them to the polls and to turn the positive hope and success of this convention into the reality of a real win in November.”

A key to a Kerry victory that is also likely to help down-ticket Congressional races is the degree to which the Massachusetts Democrat can excite the Democratic base, particularly black voters. He will rely on the advice and help of several black Members such as Clyburn, Congressional Black Caucus Chairman Elijah Cummings (D-Md.) and Rep. Sheila Jackson Lee (D-Texas), who said they would do what is necessary to rally that vote.

“Obviously we have our legislative business, but you can be assured that we are committed to being spread out across this nation to be part of this effort to change this government,” Lee said.

Erin P. Billings contributed to this report.