Functional Ambivalent has a good take on Johnny Carson —
The thing that made Carson Carson was that he never went too far.
Whatever it is in a comic’s brain that conjurs jokes instantly…the dare-devil part that starts speaking the front of the joke before the back of the joke has even been formulated…the part that synthesises personality and context and culture into a singular, funny whole…that thing, in Carson, never, ever went over the line. In 30 years on the air — much of it live — Carson jabbed hilariously at his guests without drawing blood. There were no backstage tears at The Tonight Show.
A gentleman, Oscar Wilde once said, is someone who never insults anyone unintentionally. Johnny Carson was a very, very funny gentleman.