Candidates for the Democratic presidential nomination dashed across Iowa (search) on Sunday in a final day of frenetic campaigning to turn out supporters for the first-in-the-nation caucuses.

Polls show the campaign shaping up as one of the closest in decades, suggesting a tight, four-way finish on Monday night.

With just one day to go before the Iowa caucuses, a Des Moins Register (search) poll shows Sen. John Kerry (search) has a slight lead with 26 percent, Sen. John Edwards (search) is a close second at 23 percent, former Vermont Gov. Howard Dean (search) 20 percent and Missouri Rep. Dick Gephardt (search) 18. But, with a margin of error of +/- 4 percent, the candidates are in fact in a statistical dead heat, and any of the four could easily take the lead once voters head to the polls on Monday.

Gephardt, and others, said turnout is key.

"The name of game in Iowa is who has the best ability to get the voters out," he said Sunday on NBC's "Meet the Press." "I really believe we have, my candidacy has the best ability to do that: to get our committed voters out and to bring new voters to the table who've never been to a caucus."

Asked whether he would drop out of the race should he fail in Iowa, Gephardt insisted he will win.

Gephardt knows Iowa and the stakes involved. He won the state in his abortive 1988 White House bid but lost the nomination to Michael Dukakis. The Massachusetts governor then lost the presidency to George H.W. Bush, the current president's father.

Edwards of North Carolina and Kerry of Massachusetts also planned a final day barnstorming across Iowa.

Dean was spending most of Sunday in Plains, Ga., at church with former President Carter, before returning to Iowa in the evening. Carter denies the visit constituted an endorsement of Dean, but the candidate's aides said they hope it will give him a boost in the face of new, tougher competition.

Dean and Carter met for about an hour with Carter's wife, Rosalynn, and son, Chip, who is working for Dean in Iowa. Dean later sat with Mrs. Carter in the third pew while Carter taught Sunday school to a packed church.

Speaking to reporters before the Sunday school class, Carter said he has regular conversations with both Dean and retired Gen. Wesley Clark, another candidate for the Democratic nomination.

"I'm not endorsing any candidate," Carter said. "It's kind of nice for a has-been politician to have these candidates call on you, to be remembered."

Dean, who has watched his lead in state polls evaporate as the campaign winds down, said Iowa Democrats should vote for him because "I can win."

"We have an enormous base behind us that really wants to change the country," Dean said on ABC's "This Week." "It's energy and excitement, it's what the Republicans built for a long time. Now, we've built it on the Democratic side.

Kerry, who has risen as Dean has slid in the polls, promoted himself as the only candidate with the domestic and foreign policy experience necessary for the presidency. Kerry, a longtime member of the Senate Foreign Relations Committee, also took a swipe at Dean.

"This is not the time for on-the-job training or guessing where a president might go in national security," he said on ABC. "I have been involved in those issues in a way that can give confidence to the American people that the Democratic Party knows how to make the country stronger and safer."

Edwards, who attributes his rise to his refusal to criticize his fellow rivals and backing by The Des Moines Register, predicted victory, too.

"I'm running a national campaign. I intend to be the nominee," Edwards said on CBS' "Face the Nation." "I am the candidate who can beat George Bush everywhere in America and I have a history proving I can do that."

Joe Trippi, Dean's campaign manager, also said turnout will be important. Despite the hammering the Vermonter has taken in recent campaigning, he said: "We feel very, very good about what's going to happen tomorrow in Iowa."

Trippi said on "Fox News Sunday" that Dean's organization was sending 3,500 people from around the country to knock on 200,000 doors in the state. "We think we can eke it out with our organization," Trippi said.

Two other candidates, Sen. Joseph Lieberman of Connecticut and Clark are not competing in Iowa. Clark was in New Hampshire while Lieberman was campaigning across South Carolina.