It's make or break time for the Democratic presidential hopefuls.

Polls will begin to close shortly in 10 Super Tuesday (search) states where voters were casting their choice for which Democratic candidate they most want to run against President Bush in the general election in November.

For front-runner John Kerry (search), it may be a clean sweep, giving him a particularly "super" day. With a 10-state win, pressure could be on the Massachusetts' senator's rival, North Carolina Sen. John Edwards (search), to drop out and clear the way for Kerry to slide into the nomination during the Democratic National Convention in July. National party officials are urging Democrats to unify behind one candidate.

Both candidates took a break from the campaign trail Tuesday to head back to the Senate in Washington, D.C., to vote on an assault-weapons ban proposal. Both senators backed extended the ban and closing a loophole that allows people to purchase firearms at gun shows without background checks.

The amendments were approved before the gun liability bill to which they were attached went down in overwhelming defeat.

Tuesday's cross-country contests in California, New York, Ohio, Georgia, Minnesota, Connecticut, Maryland, Massachusetts, Rhode Island and Vermont offer up 1,151 delegates. As of Tuesday, Kerry has 701 delegates to Edwards' 205. Edwards has won only one state, his native South Carolina, and that was nearly a month ago.

For more on the campaign, click to view Foxnews.com's You Decide 2004 page.

Edwards pledged to stay in the race "until I'm nominated," but said that he recognizes that, "At some point, I've got to start getting more delegates or I'm not going to be the nominee."

Edwards' advisers are hoping for wins in Ohio, Georgia and Minnesota and enough delegates from New York and California on Tuesday to keep the campaign on life support until the March 9 primaries in four Southern states — Edwards' backyard.

Polls in Super Tuesday states show Kerry with leads ranging from 10 to 40 points ahead of Edwards.

"We're going to try to do the best we can state by state," Kerry told reporters in Atlanta on Tuesday after he promoted jobs, health care and Social Security to workers at a freight and trucking depot outside the city. "I'll be back a lot," Kerry said. "We want to win Georgia."

In spite of that surge, however, Kerry isn't predicting victory nor is he hinting that his competitor should concede. The senator also isn't saying whether anyone, including his Southern colleague, is being considered as a running mate. However, he dispelled the notion that he and Edwards don't get along.

"John and I will seek each other out on the floor of the Senate, sit beside each other, talk to each other. We've talked by telephone several times during the campaign. We talked before and after every single debate," he said. "I think it is just mythology which people want to write about. I like him, I respect him, and we're going to work together, one way or the other, no matter what."

Edwards has repeatedly said he isn't running for the No. 2 spot in the White House.

Edwards also began his day in Georgia — a must-win state for him — and tried to curry favor with voters. But he wouldn't take questions from reporters.

Kerry was staying in Washington for an election-night party while Edwards plans to fly back to Atlanta to await returns in Georgia.

In Cleveland, 66-year-old John Richburg said he voted for Kerry because, in part, he believes Kerry can defeat Bush. "Bush don't mean nothing to nobody but Bush," Richburg said. "His lies done him out. He's got to go."

In downtown Cleveland, Donna James, 42, voted for Kerry but hopes Edwards will run for vice president because his working-class background resonates with northeast Ohio voters.

"I'm a Kerry fan mostly because of his position on the war and the fact that he has a little bit more experience in Congress," James said. "I'm torn between the both of them, but heads-up Kerry could beat Bush. Kerry and Edwards would be awesome together."

Kerry's 'Fire in the Belly'

Kerry remained in the nation's capital Tuesday after his vote against protecting the gun industry from lawsuits — his first vote this year — to attack Bush once again.

On the campaign trail, Kerry has all but ignored Edwards and focused his criticisms on the current resident of 1600 Pennsylvania Avenue.

"President Bush promised the American people that he would work to renew the assault weapons ban but now under pressure from the [National Rifle Association], he's walking away from his commitment as he has on so many other promises, from education to the environment to the economy," Kerry said on the Senate floor.

In their own attack, former President Bill Clinton and the Democratic National Committee sent a nationwide e-mail this week urging Democrats to donate and unify behind one candidate now that the race with the incumbent is on.

"I'll tell you this: The Republican National Committee isn't waiting. They're stockpiling tens of millions of dollars with only one purpose in mind: to deliver a devastating political blow to our nominee as soon as one is chosen," Clinton wrote in the e-mail.

"It's the only way they can win — and we cannot let them get away with it."

Kerry said there should be no doubt that he has the "fire in the belly" to spend the next eight months trying to oust Bush.

"Boy, wait until you see the fire in my belly. I didn't win 18 out of 20 caucuses and primaries so far because I don't have the fire in the belly," Kerry said in a television interview Tuesday.

"And people who know me well know that fire is raging, and on behalf of the working people of America I intend to make sure that we restore fairness in our country again."

Whereas the Bush-Cheney re-election camp has over $140 million at their disposal to use on ads and other media blitzes, Kerry is worrying about money. Fox News has learned that the DNC is planning a major multi-million dollar fundraiser to help him at the end of this month.

Cheney: 'I'm Running'

The Bush-Cheney campaign is already gearing up for a race against Kerry.

In an interview with Fox News' Brit Hume, Vice President Dick Cheney (search) assured people that he would be on the ticket with Bush in November.

Democrats, including Kerry, have been trying to portray Cheney as a liability because of his ties to energy firms and refusal to release records from his energy task force.

Cheney told Fox News that although everybody respects Kerry's service in Vietnam, the New Englander is nonetheless vulnerable on national security issues.

"What we're concerned about, what I'm concerned about, is his record in the United States Senate," Cheney said. "He very clearly has over the years adopted a series of positions that indicate a desire to cut the defense budget, cut the intelligence budget, to eliminate many major weapons programs, to vote against, for example, the first Gulf War resolution back in 1991."

Fox News' Carl Cameron, James Rosen and The Associated Press contributed to this report.