NEW YORK (AP) - David Letterman said his joke about Alaska Gov. Sarah Palin's daughter was a lousy joke, no matter how you cut it, and he's sorry.

It was "a coarse joke,""a bad joke," Letterman told viewers. "But I never thought it was (about) anybody other than the older daughter, and before the show, I checked to make sure, in fact, that she is of legal age, 18."

The joke, really, in and of itself, can't be defended," he declared.