This is a rush transcript from "The O'Reilly Factor," August 21, 2008. This copy may not be in its final form and may be updated.

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LAURA INGRAHAM, GUEST HOST: In the "Impact" segment tonight: A new study shows that when it comes to poking fun at politicians, late-night comedians may not be fair and balanced. That's a shock.

So far in 2008, President Bush, Hillary Clinton and John McCain have been the butt of most of the jokes, followed far behind by Barack Obama.

Click here to watch the segment.

(BEGIN VIDEO CLIP)

JAY LENO, "THE TONIGHT SHOW": John McCain is currently on his tour of forgotten places. He's touring what he calls forgotten places. Of course, when you're 71 the room you just walked into is a forgotten place.

STEPHEN COLBERT, "THE COLBERT REPORT": Then there's the news that Hillary Clinton's name will be put in nomination at the Democratic convention, after which I'm guessing the convention hall will implode like that house in "Poltergeist."

DAVID LETTERMAN, "LATE SHOW WITH DAVID LETTERMAN": Barack Obama is in the Mideast, and when he was over there, he met with the Israelis. Also met with the Palestinians. But, but, not to steal the spotlight, John McCain also had a very busy day. He spent the entire day in the waiting room of Just Tires.

JON STEWART, "THE DAILY SHOW": A jubilant Obama, carried to victory in North Carolina by enormous black voter turnout, felt confident enough to turn his focus to the general election. Task one: removing all visual evidence of his enormous black voter turnout from behind him.

(END VIDEO CLIP)

INGRAHAM: Joining us now from Los Angeles, James Hirsen, the author of the book "Hollywood Nation."

Now James, I know you've written about this, you've talked about this. It is so obvious, beyond obvious, that in those little production meetings, whether it's in L.A. or in New York, the idea that you're going to have some conservative stand up and say, you know something, we got to hit Obama. I mean, there are so many ways that you can hit him on his inexperience, and whether his wife is really running the show, whatever it is, because middle America is going to laugh at that. I think most of these people have no idea what middle America finds to be funny about Barack Obama.

JAMES HIRSEN, AUTHOR OF "HOLLYWOOD NATION": Well, they're out of touch with middle America. And to some extent, they're in this cocoon where everyone believes the same thing. And so, you know, and so the numbers speak for themselves.

This is an empirical study from the Center for Media and Public Affairs. It shows that the broadcast network late-night shows have almost twice as many McCain jokes as it did Obama jokes.

And look, Jon Stewart proved that you can, in fact, have a reservoir of material and have good jokes about Obama. He actually had 24 more Obama jokes. So he actually — because his show is triggered somewhat from the headlines, he showed that it's possible.

So yes, you'd have to come to the conclusion that you can't just say, I mean, some of the writers would say well, it's easier to poke fun at age, but there's enough stuff with Obama to poke fun at.

INGRAHAM: Well…

HIRSEN: ...the pretension, the way the media fawns over him.

INGRAHAM: Yes, but James, here's what I think. What also needs to be looked at is the humor that's directed at McCain is much more cutting. It's cutting to his real vulnerabilities. And I think the humor directed at Obama, it isn't quite as cutting on those issues where he's really showing vulnerability. It's kind of more around the edges and it's kind of tee-hee, giggle, giggle.

But the McCain stuff goes right to the things that people worry most about, his age, you know, whether he's, you know, nasty or has a hot temper, those kinds of things. And with Obama, it's a little more of a kid gloves approach, even when they do make fun of him.

HIRSEN: No, that's true. In other words, if there's a joke told that makes fun of Obama being a messiah-like figure or a celebrity, well, that cuts two ways because the public loves celebrities.

INGRAHAM: Right.

HIRSEN: But if the joke is told like Jay Leno did where he said that John McCain's energy program is taking three naps a day, well, that only cuts one direction. That cuts negatively. And if it's repeated enough — the recipient of the most jokes told about him is George W. Bush. And over the years, they've beaten George W. Bush's image based on the issue of his intellect. And obviously, it's been successful.

You know, one of the key things here is that this isn't just a frivolous study, because it's been shown that young voters derive a significant part of their new s information from watching these late-night shows. A study last year, they asked people who the most admired journalist was. Jon Stewart placed fourth, tied with Brian Williams…

INGRAHAM: Yes, well…

HIRSEN: ...Tom Brokaw, etc. So there's a serious aspect to this. It does influence, you know, the elections and societal attitudes and beliefs.

INGRAHAM: Well, look, these guys have all done incredibly well. They're incredibly wealthy, but I actually think they're missing the boat because I think they could make even more money and be even more popular if it appeared at least that they were a little bit more evenhanded when it comes to these political jokes because there's a lot to make fun of on both sides. And maybe — we'll hold out hope, say a little prayer.

James, we appreciate it. Thank you. Thanks so much.

HIRSEN: We're going to hope.

INGRAHAM: All right. I wouldn't hold my breath.

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