Republicans Mike Huckabee and Mitt Romney appear embroiled in an endurance test as the hours tick down to the Iowa Caucuses. A Des Moines Register Iowa Poll released Monday night showed Huckabee leading Romney by six points.

"Two weeks ago I was looking at a 22 point deficit and now it’s too close to call," is how Romney cast the poll during a New Year’s Day interview with Radio Iowa. "Some polls have me ahead. Some have the other guy ahead and some are right in the middle, so it’s going to come down to who comes out and votes."

The other guy held a news conference Monday to show an attack ad Huckabee had prepared to strike back at Romney, but then Huckabee told the assembled media he’d decided against airing it on Iowa TV. "Just a matter of not feeling that it’s the right thing to do," Huckabee said about an hour later during an interview with Radio Iowa. "I just don’t want to do it."

"You know, I just don’t think that Governor Huckabee is going to be able to fool the people of Iowa anymore than he fooled the members of the media who were there. It’s a little like somebody standing up and saying, ‘I’m not going to call my opponent any names, but if I were to call him names — here are the names I’d call him,’" Romney told Radio Iowa. "No one’s fooled by that."

The jousting between the two men has been going on for weeks. For example, Huckabee repeatedly has rejected Romney’s suggestion that Huckabee needed to apologize to President Bush for suggesting Bush has employed a "bunker mentality" when it comes to foreign policy. "I think it’s also a responsibility for a candidate for president to talk about where you are different, where you would be different," Huckabee said during a New Year’s Eve interview with Radio Iowa. "I’m not running for the third term of President Bush."

Huckabee’s betting his fortunes on a mostly volunteer effort, including families making phone calls to Iowans on Huckabee’s behalf — with the kids making calls right alongside mom and dad. "They’re here from all over America. We probably have most of the states represented — people who have just come here to help us," Huckabee said during that interview with Radio Iowa as supporters dialed away on cell phones in the next room. "…They’re paying their own expenses. It is an amazing thing."

Romney, meanwhile, has spent his own time and considerable campaign financial resources in the state to build a network of supporters but Romney told Radio Iowa that, in the closing hours, he and his staff are focused on undecided voters. "I think the biggest surprise here is that Mayor Giuliani and Senator McCain and Fred Thompson really never connected with the Iowa voters to the extent that I had expected. I thought they would be, you know, the guys at the finish line and we’d all be racing," Romney said. "But the national, well-known names just didn’t connect here in Iowa."

However, John McCain showed up in third place in this week’s Des Moines Register Iowa Poll and McCain plans to divert himself from New Hampshire to make campaign appearances in eastern Iowa Wednesday. Last week, in a swing through Iowa that his campaign had billed as his last before the Caucuses, McCain opined that a candidate "can’t buy an election" — an apparent reference to Romney — and then McCain went on to tout the value of person-to-person campaigning. "And that’s what I like so much about it," McCain said.

During a question and answer session last week in Iowa, an audience member asked McCain — who is 72 years old — whether he had the stamina to serve eight years as president. McCain offered this in response, chosing to sidestep the question and talk about the campaign. "At this time now here after all of this preparation, you know, all of the work and organization, we’re really getting into the home stretch now and it’s really exciting," McCain said. "…It’s so invigorating."

Republican Fred Thompson has said he won’t be satisfied with anything less than first or second in Iowa — suggesting his course of action will be to drop out of the race if he doesn’t reach that threshold. The Des Moines Register poll also showed Texas Congressman Ron Paul could finish ahead on Thompson, as both were knotted with nine percent support in the poll.

AUDIO: Henderson report (mp3 runs 3 min)

Republican presidential candidate Rudy Giuliani is stressing "attitude" in the closing days of the campaign here in Iowa.

"We have some big problems. We may even have some crises we have to face but this is about as well as human beings have ever been able to do it and we are the luckiest people on earth to be Americans and to have the ability to forge a future that is without limits," Giuliani said this morning in Des Moines. "…It’s all a question of attitude. It’s up to us and it’s up to strong, vigorous leadership that gets that from the American people, that harnesses that rather than decisions that get in the way of it and stiffle that kind of attitude."

Giuliani spoke Saturday morning to supporters crammed into his Iowa campaign headquarters. "2008′s going to be a great year…and the first 20, 35 days of the year are going be something like 29 primaries and caucuses, so it’s going to happen swift, fast and I believe we’re going to win and we’re going to win…with your help and your support," Giuliani told the crowd.

Giuliani grumbled about surveys which find a majority of Americans think the country’s headed in the wrong direction. "People with their heads down, people thinking America is not going to be as great in the future as it was in the past," Giuliani said. "That’s all about our decisions, I mean we get to decide if America is greater in the future or not based on the decisions that we make, the people we elect, the policies we put into effect."

As he has in the past, Giuliani stressed his "executive experience" as mayor of New York City and he mentioned the September 11th attacks five times during his 15 minute speech. Yet Giuliani’s main message was more upbeat than sober.

"I think of an America in which everybody can look up…and we can dream," Giuliani said, emphasizing the word dream. "We can dream about success. We can dream about having success."

Giuliani has not spent as much time campaigning in Iowa as some of his other GOP competitors and this will be his final trip to the state before the January 3rd Caucuses. Giuliani told reporters he is "going to do fine" in Iowa.