Yes, she was another Hollywood liberal, but not to my knowledge a publicly crusading one. In her passing I prefer to think of her best roles -- some you mentioned -- also liked "Bringing Up Baby" and her very first one, "Morning Glory." A giant of the screen, to be sure.
I do remember an interview she did with Barbara Walters, I believe, in which she said that women can't have a marriage AND a full-time career, that women
can't do it all. But she was raised a typical liberal. Spencer Tracy recalled an episode in which the family were gathered around the dinner table, arguing politics as they usually did, and arguing about taking care of the poor. Then right after dinner, Katharine's father had an encounter with a man (a hobo/homeless or otherwise poor man) who was walking across their part of the beach and Mr. Hepburn threatened to have the man arrested for trespassing. The irony was not lost on Spencer Tracy.
She's the one who was asked, "If you were a tree, what kind of tree would you be?" and she said she'd be an oak.