I never understood why Carson thought he was so funny or why he should have gotten The Tonight Show after he left in 1992.
Your right in the last 15 or so years Letterman turned into a screaming, vicious Left-Wing Liberal Socialist. Of course notice this happened after he hit it big with that show he produced “Everybody Loves Raymond” and he became really rich into the Hundreds of Millions, see then you can become a Socialist and tell everyone else what to do. I am sure he has his checkbook out for Hillary.
The only explanation is that Carson didn't want anyone to outshine him, ever; and pretty much no one has.
Carson's comedic timing was impeccable. He told a joke and the audience either laughed or in rare instances didn't laugh, at which he would make another joke about the joke having bombed. But both Leno and Letterman will tell a joke, and even if the audience laughs, they then proceed to explain the joke. It is so annoying.
Example:
"Did you hear about Joe Jones, dropped dead in the street? Ripped his suit, broke his glasses..."(Audience laughs! At this point, Carson would have gone on to his next joke, keeping the audience in stitches. But Letterman and Leno step all over the laughs by deconstructing the joke:)
"He was dead." (Audience laughter is fading.) "So did it matter if he broke his glasses? He wouldn't be needing them any more..." (a few stray titters and laughter dies.)
So boring.