COUNCIL BLUFFS, Iowa -- If it wasn't Mitt Romney, you might call it swagger.

This is something different. The hair is still perfect. His shirts are still impeccably crisp (he buys wrinkle-free shirts but still irons them). But there is less of what one voter called Romney's "accounting attitude" where "he comes across like one and one is two and everything is a figure for him."

An exacting air of striving for perfection is, of course, still present in the former Massachusetts governor. It's in his DNA.

But he is also remarkably and serenely confident as he approaches what is likely to be a very good day for him on Tuesday, when Hawkeye State voters will caucus and reveal their preference for the Republican nominee for president. Even if Romney doesn't win it outright, he is likely to finish near the top and certainly in the top two or maybe top three.

In addition, the two Republican candidates most capable of sustaining a challenge to him beyond January -- former House Speaker Newt Gingrich (R-Ga.) and Texas Gov. Rick Perry -- appear likely to finish outside the top three, badly hurting any chance they might have at gaining any momentum.

Romney came to Iowa this past Tuesday night after doing the bare minimum of campaigning in the state up until now. Nonetheless, large and enthusiastic crowds at just about every stop over the last six days have clearly buoyed his spirits, and his stump speech has come alive in response. Voters have noticed.

"I feel much better about him. I can get behind him now," said Doug Vincent, a 57-year-old logistics manager, after watching Romney speak in North Liberty on Wednesday night. "I just feel like when he speaks he's speaking from the heart. It's not BS."

Romney's body language says a lot: his gestures are sure and strong, and there is less of that stuttering, half-step shuffle in a circle while clutching the mic with both hands. His posture is no longer hunched over and closed in on itself, and his shoulders are more drawn back and wide.

"He's very, very relaxed," Stuart Stevens, one of Romney's top campaign advisers, said.

The rise of former Sen. Rick Santorum (R-Pa.) does not concern the Romney campaign, they said. Santorum has rocketed out of the low single digits in the polls to overtake all but Romney and Rep. Ron Paul (R-Texas), who was in second place behind Romney in the Des Moines Register's Saturday poll. Over the last two days that the Register's pollster was in the field, Santorum overtook Paul and occupied second place behind Romney, who led with 24 percent.

There is some potential for the Romney campaign to fear that Santorum could somehow morph into the second coming of former Arkansas Gov. Mike Huckabee, who came from behind in 2008 to deal Romney -- who had spent a fortune here in hopes of winning -- a devastating loss. Romney finished with 25 percent to Huckabee's 34 percent.

But Stevens expressed confidence that despite the full week of campaigning in the state after a year's worth of keeping expectations low for Iowa, the Romney campaign was not in any danger of being embarrassed.

"We're going to be better off the day after Iowa than we were before," Stevens said. "I don't think it's going to turn into a sand trap."

Stevens has accompanied Romney to every stop in Iowa over the last six days, and described how he often stands in the back of the room as the candidate speaks, where voters have handed him cameras and asked him to take pictures of them with their kids, with Romney in the background.

"I think most Republicans think Obama's going to lose," Stevens said. "A lot of them are coming to see someone they think is going to be the next president."

"That's new. It's a different feeling than it was a month ago," he said.

Romney's answer to questions about Santorum on Sunday was indicative of how little he feels threatened by the surging candidate. Romney cast himself as a business man and Santorum as a career politician, but as political punches went, it was decidedly on the light side.

"I can tell you that our backgrounds are quite different," Romney said. "Like Speaker Gingrich, Sen. Santorum has spent his career in the government, in Washington. There's nothing wrong with that, but it's a very different background than I have."

But for all the progress, it's not as if Romney is causing Iowa voters to swoon. The candidate who grew so flummoxed by Perry's jabs in two different debates, and by basic questions in an interview with Fox News' Bret Baier, still lurks close beneath the self-assured exterior.

And there is a tangible lack of an emotional connection between Romney and most voters that still -- at this late date and with everything having gone so profoundly well -- keeps Romney from closing the deal, both in Iowa and with Republican voters nationally.

"He has a tendency to be very efficient. I don't like his accounting attitude but I like his efficiency," said Eugene Turner, a 66-year-old factory worker in Griswold.

Turner came to see Romney at the Family Table Restaurant in Atlantic, but when asked if he was supporting Romney, he said, "Yes and no."

"I haven't made my mind up," Turner said, though he didn't appear ready to support anyone else. Santorum, he said, "hasn't been under the scrutiny long enough and I just don't know enough about him."

And Romney, a former private equity executive -- who is estimated to be worth around $200 million -- still doesn't strike some voters as someone who gets what they're going through in tough economic times.

"He's moneyed. I'm not sure that's a good thing. I'm not sure he understands common people," said Charles Seamans, a retired minister from Cedar Rapids.

The Romney campaign is well aware of this Achilles heel. Because of this, and perhaps in an attempt by Romney not to lapse back into his more rigid self, he has been pressing forward in his interactions with voters. He is refining his remarks to include lines meant to show empathy and is injecting humor -- a brand of humor unique to him -- into his comments.

"These last three years have been tough, for a lot of people. You know that. I think this is a detour, not a destiny for America," said Romney on Saturday night in Sioux City.

"I want you to remember," Romney told voters, "what it was like when we were thinking about what movie we were going to take the kids to at the end of the week, instead of wondering how we're going to make meals that will last until the end of the week."

A few heads in the audience nodded.

Sunday night, Romney tossed out a pop culture reference, joking that the gap between promises made by President Obama and his actual accomplishments "is the largest that I've seen since the Kardashian wedding and 'til death do us part."

And when a young woman in Sioux City asked Romney to make a candy known as Pop Rocks more accessible -- probably the oddest question witnessed by a Huffington Post reporter at any political event in recent memory -- Romney ran with it.

"I used to remember those. It's been along time since I've had Pop Rocks," Romney exclaimed, and then transitioned to a joke about President Obama. "There are a lot of things I can blame on the president. But I'm not going to blame him for getting rid of Pop Rocks. I'm afraid the market just wasn't there."

Most of the time, however, Romney has attacked Obama with relish, if not as ferociously as a Gingrich or Perry. In an interview with The Huffington Post on Thursday on his campaign bus, Romney compared the president to Marie Antoinette, the French Queen who was overthrown during the French Revolution, but who said of the poor, dismissively, "Let them eat cake."

In his remarks to voters, Romney has portrayed the president as "pessimistic" about the nation's future, while declaring that he himself is hopeful about bringing back a "bright and positive future."

"I don't think that America's gone. I think it's still out there. I want to reclaim that America," Romney said.

Stevens said Romney's knocks on Obama were a sign that the candidate was already starting to look ahead to a general election showdown with the incumbent president.

"The campaign is entering a different stage now," Stevens said.

UPDATE: In a follow-up email, Stevens said he did not mean to imply that Romney is already looking to the general election, merely that the Republican primary process is moving into a new phase.