Democratic presidential candidates are preparing for a wide-ranging test of their popularity as campaigning begins for contests in seven states.
Candidates will be criss-crossing the country to promote themselves
The contenders vying for the party nomination face primaries next Tuesday in Arizona, Delaware, Missouri, Oklahoma and South Carolina.
New Mexico and North Dakota will be holding caucuses on the same day.
John Kerry enters the "Super Seven" stakes as front-runner after his victories in Iowa and New Hampshire.
"I ask Democrats everywhere to join us so that we can defeat George W Bush and the economy of privilege," Mr Kerry told supporters before heading to St Louis, Missouri, for a campaign rally.
Mr Kerry's convincing win in the New Hampshire state primary on Tuesday has boosted his bid to become the Democrats' challenger to Mr Bush in November, correspondents say.
With all votes now counted, final results give the Massachusetts senator 38%, compared with 26% for closest rival Howard Dean.
About 200,000 voters participated in the primary - well above the previous record of 170,000 in 1992, when Paul Tsongas defeated the future Democratic nominee and president, Bill Clinton.
3 February: "Super Seven". Primaries and caucuses in Arizona, Delaware, Missouri, Oklahoma, South Carolina, New Mexico and North Dakota. Virginia Republican caucuses
7 February: Democratic caucuses in Washington and Michigan
8 February: Democratic presidential caucus in Maine
Last week, Senator Kerry was the surprise winner in the first stage of voting in Iowa.
Correspondents say the scale of Senator Kerry's win will give him vital momentum for the primaries that lie ahead.
But Mr Dean, the former Vermont governor who improved on third place in last week's Iowa caucuses, said he was pleased with his performance.
"We did what we had to do," he said on Wednesday. "We got some momentum back in the campaign, but it's going to take a long time to get back the momentum we had as front-runner status."
Mr Dean is due to begin a seven-state tour on Thursday.
Despite the excitement of the first two contests, the biggest hurdles in the race for the White House still lie ahead.
The BBC's Justin Webb in Washington says Iowa and New Hampshire matter because if candidates do very badly, their campaigns normally fall apart.
Wesley Clark is still viable, despite his third place in New Hampshire
However, if several contenders pass the early tests, the snowy wastes of the north are soon forgotten - because the bigger states, with large numbers of delegates' votes to be tied up, are in the rest of the country.
This means that retired General Wesley Clark and Senator John Edwards, who came third and fourth in New Hampshire, are still viable candidates.
Senator Joe Lieberman pledged to continue his campaign despite trailing in fifth.
The Democratic race is the current focus for the US election campaign, since no Republican challenge to Mr Bush seems likely.