I watched Johnny Carson sometimes towards the end of his run but don't recall if there was anything political. If there was it would have been lighthearted and not designed to make people mad.
He said he doesn’t talk about politics because he’s following in the footsteps of other great comedians - Jack Benny, Red Skelton, etc, who used their shows to entertain.
He also said he thought it would be a terrible idea to use the Tonight Show to push political views. He didn’t think a person in that position would be able to keep from (I’m paraphrasing) becoming self-important.