Last week, David Letterman landed on the National Organization for Women's Media Hall of Shame, joining Glenn Beck and G. Gordon Liddy. For the sake of consistency, the notoriously humorless organization has put itself in the position of denouncing every comedian and talk show host it believes contributes to "the sexualization of girls and women in the media."

Good luck with that. But if NOW is true to its mandate, Letterman will soon be joined in the Hall of Shame by Bill Maher, Jimmy Kimmel, Conan O'Brien and every one of their late-night brethren. As everyone who channel hops knows, television is libertarian and purposely devoid of egalitarian impulses after 11:35 p.m. Late night is the place where "refined" humor goes to die amid crudity and the "sexualization" of everyone.

Letterman earned both barrels from the venerable women's organization for joking about Alaska Gov. Sarah Palin and one of her daughters during the Palin family's recent trip to New York City to receive an award from an autism foundation.

"One awkward moment for Sarah Palin at the Yankees [game]," Letterman said. "During the seventh-inning stretch, her daughter was knocked up by Alex Rodriguez." The audience laughed, immediately understanding it as a reference to 18-year-old Bristol Palin, the governor's oldest daughter and single mom now barnstorming the country advocating sexual abstinence for teens.

Meanwhile, A-Rod has been a pinata for Letterman ever since his messy divorce and public dalliance with Madonna last year. Since then, the Yankees' slugger has been reported in the company of one beautiful starlet after another. Implicating him as the father of Bristol's next child is either funny or irredeemably tasteless.

Groans are usually the first sign that a comic has crossed the line of arbitrary propriety, but none could be heard from the audience that night. Pleased with the joke's execution, the veteran talk show host moved on as he's done every night for 27 years. There was nothing particularly memorable about such a lame joke until the Palin family -- looking for a fight -- chose to interpret it as a reference to their 14-year-old daughter Willow instead of 18-year-old Bristol.

As the mother of the person referred to in the joke, Gov. Palin is entitled to take it as literally as she wants. She knows it wasn't meant as flattery. Letterman was picking at an open wound for the Palins. "Laughter incited by sexually perverted comments made by a 62-year-old male celebrity aimed at a 14-year-old girl is disgusting," the Palins said in a statement indicating they weren't willing to give Letterman the benefit of the doubt.

The conservative end of the blogosphere also went ballistic. Spearing the comedian would be righteous payback for Sen. John McCain having to grovel on Letterman's program during the final weeks of his presidential run last year. Nobody is shocked that the Palins' political allies are willing to demagogue this for all its worth.

The following night, Letterman spent several minutes explaining the previous night's joke. No, he was not advocating the statutory rape of a 14-year-old. Yes, he conceded that his material was often tasteless. He offered the family an opportunity to appear on his show for an on-screen apology, but Gov. Palin scotched that by saying Willow now feared being around the comedian.

Outraged conservatives complain that "liberal" late night TV hosts rarely joke about the Obama girls. That's because we don't know anything about them except that they're cute and smart. We know way too much about Bristol's sex life and the antics of the Palin family.

There has to be some relationship between the object of ridicule and real life for a joke to work. Telling a joke about Jimmy Carter shooting someone in the face isn't going to get the same laughs as Dick Cheney spraying a lawyer with birdshot while hunting flightless birds.

You don't have to be a Letterman apologist to point out that every late-night comic has joked about Bristol Palin in the past year. It's interesting that Jay Leno and Conan O'Brien have done more Bristol Palin jokes than anyone, but Letterman is perceived as meaner and more "partisan." (Here's a Web compilation of Bristol Palin jokes.)

When Gov. Palin runs for the Republican presidential nomination in 2012, she'll take Letterman up on his offer to kiss and make up in front of millions of potential voters. She'll even do a Top 10 List about putting lipstick on a pig. Ratings will go through the roof.