— After five years of getting to know Mitt Romney, some Iowa Republicans still don’t feel like they know the guy. He’s too polished, they say, too perfect, too cool.

To remedy that, the former Massachusetts governor dispatched one of the Republican Party’s least polished, most imperfect and hottest stars here on Wednesday night to open a window onto Romney, who is struggling four weeks before the Iowa caucuses to convince Republicans to let him be their standard-bearer.

New Jersey Gov. Chris Christie, addressing about 100 Republicans in the lobby of a family-owned convenience store chain’s headquarters here, got right to the point: “If you’re looking for a candidate who agrees with you on everything, buy a mirror.”

Instead, he added, “When you look at these extraordinary candidates, say, ‘Is this the kind of person that is always going to make me proud in the Oval Office — and I never have to worry whether they’ll embarrass America, that I never have to worry will do something that will make me ashamed?’”

That kind of person, Christie said, is Romney. “Maybe we should expect at least that from our leaders, but we’ve learned over time that we don’t always get it,” he said.

Christie talked about an afternoon in October when Romney and his wife, Ann, visited him and his wife, Mary Pat, at the governor’s mansion in New Jersey for lunch. They sat in the back yard for two and a half hours, with the Christies’ kids cycling in and out on their skateboards and roller blades.

“He spent as much time talking to my children — I have four of them, between 8 and 18 — than he spent talking to me and Mary Pat,” Christie said. “You can’t fake that. Politicians can be taught to fake a lot of things. You can’t fake that. This is someone who I’ve come to know has an extraordinary heart. He loves his wife, he loves his children and he has absolutely no hesitation in showing that affection openly.

“Now that’s not what you see on TV all the time,” Christie added, “but I sat in my back yard for two and a half hours and watched him talk to my children.”

A few days later, Christie traveled to New Hampshire and endorsed Romney. He has been a powerful surrogate for Romney, on the campaign trail here and in New Hampshire, and is helping mobilize his financial supporters on Romney’s behalf.

Christie never singled out former House speaker Newt Gingrich — or, for that matter, any of Romney’s other rivals — but the contrasts he drew between Romney and Gingrich were clear.

“We’ve seen for the last three years what it means when we have a legislator as president,” Christie said. “I have nothing against legislators.. . .But they’ve never run anything. They don’t know how to run something. And we have seen what it’s like to have someone in office who doesn’t have the first idea of how to use executive power or how to exert real leadership.”

Asked later by this reporter whether he was concerned about Gingrich’s surge in the polls, Christie said: “Nope. Lots of people have surged in the polls out here. I wasn’t concerned about Michele Bachmann or Herman Cain or Rick Perry. Mitt Romney is the steady, mature leader we need for our party and our country.”

Christie told the audience here that whenever Romney asks his advice on a subject, he always tells him: “Be yourself.”

Christie has developed a national reputation for his often brash straight talk. This fall, he weighed a presidential run of his own, but opted against it. Asked here whether he would consider running in the future — say, in 2020, if Romney were elected to two terms — he said he would think about it.

“If people like you and others think I have something positive to offer, then I may well be able to get a job, so we’ll see how it goes,” Christie said.

When one voter — apparently drawing a contrast of girth between President Obama and Christie — yelled out, “We don’t necessarily want lean and mean. We’ve got that now,” Christie replied: “Then I’m your kind of guy, buddy!”

Christie playfully dismissed talk of being Romney’s running mate.

“Do I look like somebody’s vice president?” he said. “I find it hard to believe that somebody would look at me and go, ‘Yeah, that’s the guy I want standing behind me nodding my head for the next eight years.’ It kind of would be like Secretariat in the gate at the Belmont, you know? It would be a little bit hard. So I don’t think Governor Romney will ask me.”

“I wouldn’t bet on Romney-Christie. But one never knows. We live in hope.”

A couple minutes into Christie’s remarks, about a dozen protesters interrupted him and chanted, “Put people first,” “Make Wall Street pay” and “Mitt Romney and Chris Christie are part of the 1 percent.”

They continued screaming for about two minutes before security and campaign officials escorted them out of the venue. While they were chanting, Christie nonchalantly autographed people’s Romney campaign signs. At one point, he mocked the protesters.

“You’re so angry, aren’t you?” he said. “So angry. So terrible.. . .Work it all out for yourselves. Hey, listen. You know what? We’re used to dealing with jokers like this in New Jersey all the time.”

After they left, he continued his riff. “They’ll be working at the Marriott down the street. Please remember to tip your waiters and waitresses. Let’s see. Where was I before I was so New Jersily interrupted?”

Christie said the protesters’ anger was “rooted in the fact that they believed in this ‘hope and change’ garbage that they were sold three years ago by this president.”

“Now they’re angry,” he said. “But they’re not mature enough to know they should be angry with themselves. So they’re going to be angry with me or Governor Romney or some of you.”