I guess Carson saw in Letterman someone more like himself - inherently mean...difference being that Carson could actually be funny.
Carson was also a womanizer, but Letterman also exceeds him in that category. When he moved to CBS, the network built him an apartment in the back of the Ed Sullivan Theater, and people I know at the network claim that Dave still spends a lot of time there, while his wife and son live in a luxury apartment in Manhattan, and he's got three or four other houses scattered around the globe.
You'll recall when Letterman's sex scandal broke (on the same weekend as Tiger Woods’s), he confessed to multiple affairs with young women working on his show. And, if his concubine's boyfriend (a 60 Minutes producer) hadn't tried to blackmail Letterman, the scandal would have turned out much differently. As it was, Letterman became the “victim,” and there wasn't much concern about his long-suffering girlfriend/wife (Regina Lasko), or his young son.
But it's not quite over for Dave. Yesterday, his production company was hit with a lawsuit over its treatment of interns on the show, specifically the fact they are not paid. I've got a strong hunch that Letterman's carousing with female staffers will figure prominently in the court case, as part of the “hostile work environment” at Worldwide Pants. There is a reason the former interns (and their lawyers) are going after Dave, and it goes far beyond the lack of pay for interns.
Carson could certainly be a jerk—read Henry Bushkin’s book—but Letterman takes top honors as a misogynist And like Johnny, he has a long history of cutting off former staffers who no longer fit his plans for the show. Examples of that include his former executive producer, Robert Morton, and his longtime announcer at NBC and CBS, the late Bill Wendell. Letterman didn't even have the grace to tell Wendell in person that he was being replaced. What an ass.