I'm confused you see. I don't understand why the governor that should quit hasn't, and why the one that I would have expected to stay in didn't. Mark Sanford should quit, not because he had an affair, but because he himself said in the past that adulterous politicians (Bill Clinton notably) had lost the moral authority to govern. Now I disagree with his thesis, but it is his and if he really believed it he should step down. Of course, I'd accept him just admitting that personal behavior should have no bearing on public office too.
Sarah Palin I don't understand. I thought I did, but clearly I don't. If she truly stepped down because she felt she was a liability to her state (ie. the 18-and-counting dismissed cases of alleged ethics violations and the so-adversarial-that-nothing-can-get-done-legislature) then I have to give her credit. Of course, I expect that if she were to try to run for the Republican nomination in 2012 she'll be savaged by her competition within the party for "not fighting through it" or whatever else.