As Romney breaks away, the 'Reagan Rule' of not attacking fellow Republicans is tossed aside

This is a rush transcript from "On the Record," January 10, 2012. This copy may not be in its final form and may be updated.

GRETA VAN SUSTEREN, FOX NEWS HOST: Early in this political contest, Congressman Michael Grimm of New York endorsed Governor Mitt Romney, and he hit the campaign trail from here in New Hampshire. Congressman Michael Grimm joins us. Good evening, sir.

REP. MICHAEL GRIMM, R-N.Y.: Good evening.

VAN SUSTEREN: So, I guess you had a good night?

GRIMM: We had a great night.

VAN SUSTEREN: Well, it's good you enjoyed today, because wait until you get down to South Carolina. It's not going to be so pretty.

GRIMM: Oh, I don't know about that. I think quite the opposite. I think that after Iowa and then tonight, there's a lot of momentum behind Governor Romney. You're also seeing the fruits of someone who put together a very good campaign, systematic, well-planned, professional. And that's bearing fruit now. And that's I think indicative of the type of president that he's going to be.

VAN SUSTEREN: All right. So, for the fact that the knives are coming out in South Carolina already. I heard about a half an hour ago with Sean Hannity, Governor Rick Perry referring to him not as a venture capitalist but as a "vulture capitalist." It's also quoted all over the South Carolina papers.

There's a 28-minute video coming up by Speaker Gingrich supporters that hammers him. So, I want to say it's not going to be particularly pretty the reception tomorrow in South Carolina. South Carolina is demonstratively different than the campaign hall tonight.

GRIMM: No question. The unfortunate thing and the thing that I worry about most is how this affects Republicans as a whole. I don't think this is very healthy for the Republican Party. I think this sends a mixed message. It's almost siding, you know, with those on the other side of the aisle, pitting us against Wall Street.

The last thing we want to do is divide this country anymore. That's what President Obama has done. So, here, I see Governor Romney coming in and trying to unify us, trying to bring this country back together. That's exactly what he needs to do, because that's what we need.

VAN SUSTEREN: Yes. Except for the fact that what's good for the goose is good for the gander. He just did the same thing or his supporters out in Iowa to Speaker Gingrich. I mean, the knives were out for Speaker Gingrich, and it took its toll on Speaker Gingrich. He took a dive.

So, it's a little bit harder for him. Governor Romney is sort of, you know, talk about being, you know, big, you know, and having everyone join together. I mean, he can fight.

GRIMM: There's no question, and I have no problems with -- I have broad shoulders, myself, and I know the governor does, but again, this is now a different ideology and different philosophy. We're going to use tactics --

VAN SUSTEREN: No. He's winning now.

GRIMM: No, with the tactics that I would think -- I would really expect from President Obama to be using, and that we've seen used before by the left against the right. If the right starts using that against ourselves, and really, what is, you know, the question? What does the Republican Party stand for? I don't think it's healthy for Republican Party.

VAN SUSTEREN: Boy, it may not be healthy for the Republican Party, but you know, it's like everyone -- a lot of people who are Governor Romney supporters are now upset that people are going after him. When his Super PAC really was aggressive and everyone saying now that Speaker Gingrich is angry or something like that.

Look, because he fought back. he fought back against it. So, I mean, you know, it seems a little bit, you know, all of a sudden, everybody wants to sort of holier than thou about it.

GRIMM: No, I wouldn't say that. It's just -- again, as a Republican, as a freshman member of the House, I look at the overall picture and I think one of the problems that we have in this country is that we've become so polarized. And if our own party is going to polarize within and pit each other against, I just don't like anyone pitting anyone against success.

America stands for the land of opportunity. The ability to be successful should be a good thing. I would want to teach my children someday that they should strive to be successful. So, in anyway pitting against that success, I think that's hurtful to the United States as a whole and that's not a good message.

That doesn't mean they can't come out aggressively and fight a good fight. I mean, I have no problem with that, because I know the governor can defend himself as he has. But again, that's a dangerous area to go for Republicans, and I certainly don't think that, you know, Ronald Reagan would be proud right now. That's just caught in a rule.

VAN SUSTEREN: Well, I think it's going to be a little bit fiercer struggle in the days to come before it all get started. But, it'd be nice if we're on the same team. Anyway, congressman, nice to see you, sir.

GRIMM: Great to see you, as always.