DES MOINES -- Presidential candidates hit the campaign trail in Iowa at a frenzied pace over the weekend, working to earn votes in the waning days before Thursday's first-in-the-nation caucuses.

With Democrats Barack Obama, Hillary Clinton and John Edwards locked in a tight three-way race, the trio fanned out over the state working to turn out their backers on caucus night and win over undecided voters.

Edwards revved up a crowd of more than 1,000 at a high school in working-class neighborhood on the east side of Des Moines Saturday night.

Edwards told the audience that his campaign's momentum is growing in the closing days of the campaign. He worked to drive home his populist message with the crowd, pledging to take on the corporate interests he said have a stranglehold on the country's democracy.

"The truth of the matter is, you have to beat these people," Edwards said. "You have to take them on and take them on in a tough way, because if you don't, nothing will change. They are not going to lay down."

Clinton attended church services Sunday morning at a predominantly black church in the central part of Des Moines in the midst of a weekend of heavy campaigning.

In remarks to the congregation, Clinton highlighted her work on behalf of children.

"Our Lord has said on many occasions that we are like children, and he wanted to bring the children to him," Clinton said. "We as a nation must fulfill that call."

In a high school gymnasium in Newton, Obama underscored his case that he is the Washington outsider in the race. He said the country can't wait to fix its health-care system, provide good-paying jobs and end the war in Iraq.

He also took on critics who said he is too nice to change the country.

"We have to stand up in five days and bring about real change, meaningful change," Obama urged the crowd.

Dallas Gilreath, a West Des Moines Democrat, said he will likely support Democrat Bill Richardson in the caucuses, citing his resume as a governor, former U.S. energy secretary and former U.N. ambassador.

"He's had that experience that none of the rest of them have," Gilreath said.

But Gilreath said he didn't know if Richardson would be able to gain enough support to reach the "viability" threshold of 15 percent at his local caucus. If that happens, Gilreath said Obama would probably be his second choice.

Republican Mitt Romney's campaign traversed Iowa this weekend in his Mitt Mobile -- a red, white and blue RV -- stopping at local businesses in an effort to shore up support.

"It's easy showing up here and getting a cup of coffee in the morning, but I need you to show up at the caucus," Romney told supporters in an Altoona coffee shop Saturday morning. "So go to the caucus. There's nothing on TV, just the Orange Bowl."

The months of rigorous campaigning in the Hawkeye State appeared to take its toll on Romney, who misspoke when thanking Iowans for their support.

"I won't remember my friends here in Iowa. You've been an inspiration to me and Ann -," Romney said before his wife, Ann, corrected him.

"I said, 'I won't forget," Romney said to the giggling crowd. "This is good. This is like spell check right here, you know," the candidate said referring to his wife.

Even former New York mayor Rudy Giuliani, who has focused his presidential campaign on other states, swooped into Iowa for a series of campaign events over the weekend.

At a meeting with supporters at his Iowa headquarters Saturday, the Republican stressed the need for a strong leader as the country fights terrorism.

Giuliani argued that his resume, including his leadership after the Sept. 11 attacks in New York, would make him the most experienced candidate to lead homeland security efforts.

Giuliani said the country must stay on offense against terrorism with a strong military and strong intelligence.

"We need to anticipate as much as we can what these terrorists might do and stop them before they do it," Giuliani said.

Contact Charlotte Eby at (515) 243-0138 or chareby@aol.com.