If I understand this correctly, Sarah Palin likes to speak of herself as a pit bull with lipstick.  That is, a dog with a reputation for savagery and unpredictability, for turning on people it is close to and mauling little children without warning.  That is okay; it is better than okay, it is humorous and self-aggrandizing.
But if you ever use the old canard about lipstick on a pig, ever again, well, you've just been insensitive and maybe hurt the pit bull's feelings, and you'd better apologize ASAP.
Who's being sexist here?  Can you say "double standard"?