This is a rush transcript from "The O'Reilly Factor," September 25, 2008. This copy may not be in its final form and may be updated.

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BILL O'REILLY, HOST: In the "Kelly File" segment tonight: Perhaps the most vicious political ad of the campaign is running on MSNBC. FOX would not run something like this. CNN reportedly turned it down. Roll the tape.

(BEGIN VIDEO CLIP)

UNIDENTIFIED MALE: The relevance of knowing the details of his course with melanoma are very important. Another bout of cancer for John McCain while he's president of the United States would profoundly impact his capacity to lead.

UNIDENTIFIED MALE: Melanoma is the deadliest of skin cancers, and the chances of survival if you have melanoma spread through your body are very, very slim.

UNIDENTIFIED MALE: Brave New PAC and Democracy for America are responsible for the content of this advertisement.

(END VIDEO CLIP)

O'REILLY: Now, that ad was put out by two despicable human beings. Far-left hatchet man Robert Greenwald is a notorious smear merchant, a failed Hollywood director who has made a career out of doing stuff like this, and James H. Dean, Howard Dean's brother, had a hand in the ad, as well.

Also, the atrocity continues. The pattern of behavior sanctioned by GE, General Electric, Chief Jeffrey Immelt and NBC News boss, NBC boss, Jeff Zucker. They should be ashamed, but they are anything but.

With us now to analyze the legal implications, attorney and FOX News anchor Megyn Kelly.

I don't think most people understand this wasn't put out by the Obama campaign.

MEGYN KELLY, FOX NEWS ANCHOR: No, definitely not.

O'REILLY: I don't think the Obama campaign knew about it, because this is suicide for any political candidate.

KELLY: I've spoken with the campaign. They had nothing to do with it.

O'REILLY: All right. Because it would be suicide for them to do it. This is so down...

KELLY: They would not do this.

O'REILLY: Showing the man's scars, it's awful. But McCain-Feingold — isn't this ironic? — allowed this to happen. Explain that a little bit.

KELLY: Well, you've got these groups, PACs, political action committees. Those are the two groups behind this ad. And they are allowed to take donations. They can get more in individual donations than the candidates can, and then they use that money for things like this, and it's totally legal. They can get millions of dollars from the collective, and they use it for things like this, and it's perfectly legal as long as they don't "coordinate" with the campaigns. It's not legal if they have done any coordination with the Obama campaign or, for that matter, with the DNC on an ad like that.

O'REILLY: Howard Dean's brother…

KELLY: Well, just because he's brothers with the guy who was behind this doesn't mean they coordinated, and in fact...

O'REILLY: Let me stop you there. So Howard Dean's brother is behind the ad.

KELLY: Right. That's clear.

O'REILLY: And Howard Dean is the head of the DNC.

KELLY: Right.

O'REILLY: Now, you're telling me that there is no coordination between brothers?

KELLY: That's what they say. They say...

O'REILLY: Who says?

KELLY: The two do not discuss it at dinner.

O'REILLY: Who said that?

KELLY: According to a representative of the PAC.

O'REILLY: That put this out. OK. OK.

KELLY: James Dean's brother.

O'REILLY: All right. Shouldn't the FBI, or the Federal Election Commission, investigate because of the closeness of the brother connection?

KELLY: No.

O'REILLY: If you were the attorney general of United States, and I wish you were, wouldn't you order that to happen?

KELLY: No, I wouldn't.

O'REILLY: Really?

KELLY: We're not going to waste our taxpayer dollars on that.

O'REILLY: We're not?

KELLY: It's a different story if you've got hard-core evidence that the two are coordinating.

O'REILLY: They're brothers.

KELLY: That doesn't matter.

O'REILLY: No?

KELLY: They're brothers. That would by nature mean that any candidate couldn't have a family member who was at all related to a PAC. That's not the rule. As long as they're not discussing it...

O'REILLY: But shouldn't we put them under oath and ask them that question?

KELLY: No, not unless you've got — it's just like filing a lawsuit. You have to have charges or charge someone with a crime. You have to have probable cause.

O'REILLY: What if I called you and I said I think they might have talked about it? Not good enough? OK.

KELLY: Not good enough. No. You need — the feds never get involved. I mean, the election commission does oversee these things, right? The SEC does an oversight, but they don't get involved unless something blatantly obvious and dirty is going on.

O'REILLY: All right. So just recapping, these PACs, political action committees, can get as much money as they want pretty much.

KELLY: Pretty much.

O'REILLY: Nuts give them money on both sides.

KELLY: On both sides, absolutely right.

O'REILLY: And they put any kind of ad they want to put out.

KELLY: Yes.

O'REILLY: The only people that would run the ad are NBC. That's it. CNN, FOX, no way, not doing it, because look what's in it. So NBC, they find a home over there, which tells you really pretty much all you need to know about General Electric and NBC. And they run the ad, and there's absolutely nothing anybody can do about it.

KELLY: Yes, pretty much. You have it exactly right.

O'REILLY: Although the court of public opinion certainly, I think most folks, decent folks...

KELLY: But what are the public opinion going to do? They're not going to...

O'REILLY: Not watch NBC News. Punish NBC News.

KELLY: Maybe they'll do something with respect to the news organizations.

O'REILLY: Right.

KELLY: But there's no retaliation against the PAC. And I don't think — and the Obama supporters aren't going to hold this against him. Now, he hasn't come out and denounced the ad, and I don't expect him to, because generally...

O'REILLY: I don't know if he even knows about the ad.

KELLY: Well, generally the campaigns just haven't gotten involved, have chosen not to get involved in snipping about each other's PAC ads.

O'REILLY: All right. Have you seen any ad on the McCain PAC side, the right-wing side, like the Swift Boat stuff against Kerry? I haven't seen anything about…

KELLY: They've gone after him hard on the Reverend Wright, William Ayers.

O'REILLY: But it hasn't been anything like that though.

KELLY: Well, this is a personal, vile attack on John McCain. Listen, whether you think his medical records are fair game or not, the up-close and personal shot of his scars and the suggestion that he's going to die soon, I'm sure that went over well with his family. I mean, it's just cruel.

But I'm sure Obama supporters would say some of the ads tying him to some of these characters in Chicago were cruel or at least unfair as well.

O'REILLY: I watched those ads, and we've been investigating Wright and Ayers. And we've done our own "Obama Chronicles." I haven't seen them, but maybe I'll have to look at them again.

KELLY: They're on the Internet, Bill, too.

O'REILLY: I know. But we have them — Amanda Carpenter we have every week, coming on the Internet, telling us what's there and what isn't, so we're aware of it. But I haven't seen anything like that.

All right. Megyn, keep an eye on it. We appreciate you coming in, as always.

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