Gregory Kane: Who is laughing now, Mr. Letterman?

Letterman, who probably needs better joke writers as well as some kind of male chastity belt, wisecracked that New York Yankees player Alex Rodriguez “knocked up” Palin’s daughter during a seventh-inning stretch.

Palin went ballistic, figuring Letterman was referring to her 14-year-old daughter Willow. Letterman countered by saying he was referring to her 18-year-old daughter Bristol.

Apparently, Letterman’s writers forgot Palin has two daughters.

In a Newsday story from June 10 of this year, Letterman offered some kind of lame apology to Palin: “I would never, never make jokes about raping or having sex of any description with a 14-year-old girl.” He added: “I mean, look at my record. It has never happened. I don’t think it’s funny. I would never think it was funny. I wouldn’t put it in a joke.”

Recently, Letterman was forced – by an alleged extortionist – to come clean about his record. No, he wouldn’t have sex with a 14-year-old girl. But the married Letterman revealed that he does like having sex with women other than his wife, and apparently he likes them young. And they’re all staffers at “Late Night With David Letterman.”

Boy, talk about the Coolidge Effect.

The reporter who wrote the June Newsday story opened with this, we now know using hindsight, prophetic line: “Effectively accusing David Letterman of being a dirty old man, Sarah Palin yesterday ripped the late-night host for making crude jokes about her 14-year-old daughter, but Letterman last night claimed he was talking about her other daughter.”

It turns out Palin was absolutely right: Letterman is a dirty old man, so sullied with horniness that he felt compelled to apologize about his numerous affairs with female staffers to his co-workers and his wife.

And to Palin, according to the Web site, www.newser.com. “And now also,” Letterman was quoted in the story, “because what can it hurt, I’d also like to apologize to the former governor of Alaska, Sarah Palin. I’m terribly, terribly, sorry.”

If Letterman has a dog, I’d bet good money he apologized to the pooch, too. But did he apologize to Palin for the misunderstanding about whether he was referring to Willow or Bristol, or because he dragged one of her children into the mess?

Palin, as a vice-presidential candidate, was fair game for comedians and satirists of every stripe. Her children are not fair game. But some comedians don’t realize that.

One of the most offensive – in fact, one who revels in being offensive – is a woman called Lisa Lampanelli. Earlier this year she did an HBO special, targeting Palin and her children.

“How many kids does this b***h have to have?” Lampanelli continued. “And then she goes and has the retard kid. What the bleep was that bleep all about? That is God’s way of saying ‘Stop the presses.’ The retard kid is the warning shot of the reproductive system. That is nature’s way of saying put the police tape around your bleep and close its doors.”

Lampanelli stopped just shy of advocating that Palin’s developmentally disabled child be euthanized, but I have a hunch she wouldn’t be against it, either.

What Letterman said is nowhere near as offensive as what Lampanelli said, but he sure as heck was in a much cleaner pew of the same church.

And in that church, it’s OK for Letterman as a late-night talk-show host to be an attack dog against conservatives. President Obama got the buddy-buddy treatment when he appeared on Letterman’s show; Palin got crude jokes about her children.

If Palin is somewhere cackling hysterically about Letterman’s situation, I can hardly blame her. She probably isn’t, an indication that what many of her critics said about her simply isn’t true.

But at least Letterman probably realizes that now.

Examiner Columnist Gregory Kane is a Pulitzer-nominated news and opinion journalist who has covered people and politics from Baltimore to the Sudan.