But his attacks on Alaska Gov. Sarah Palin are much more than that.
Indeed, the late-night comedian managed to anger all sides with his nasty mocking of the Palin family -- particularly his snotty wisecrack that while Palin was visiting New York, her daughter (age 14) was "knocked up" by a Yankees player: Both the conservative Concerned Women for America and the liberal National Organization of Women denounced the remark.
Letterman's attempt at humor revealed a sorrowful remnant of the cavalier manner in which society used to regard young women.
But something even bigger is at work. Letterman represents a left wing that looks down their noses at traditional American values and cackles anytime a supporter of those values -- however young and foolish -- falls short of such ideals.
In short, it's open season on conservatives -- and their children are fair game. Ever since Gov. Palin arrived on the national scene, the liberal media have been desperate to tear her down. Someone so engaging, popular and conservative can't be allowed to gain political power. The media seemed to want to nip that in the bud.
So people like Letterman snear and giggle and say she's got a "slutty flight attendant" look.
These aren't just harmless jokes. They're a purposeful attempt to smear and cut down rising conservative politicians before they become too powerful.
If they have to go after her children in the process, well, those are just jokes, right?