First... we need to define "sexist". Let me break the examples of alleged sexism into three groups.
1) The "offensive sexist" jokes (i.e. talking about female dogs or body parts ) are on the fringes. These are not part of the Obama campaign.
2) Then there are questions about whether she is frighteningly unsuited for the job which are being tagged as "sexist"
3) Then there is SNL type skits in the national media that make fun of her public persona which are also being tagged sexist.
The first category is background noise. Offensive jokes are made about every single public figure. There is no way to stop them, and some people obviously think they are funny (and some of them I may even laugh at over a beer). As long as the Obama campaign is not part of this... then what's the big deal. This is just part of the society we live in.
The second category is a bit tricky, but a again it is part of political life. Michael Dukakis, Eagleton, Stockton ... history is full of candidates who were shown to be completely unprepared for the job. The press is happy to take the job of showing candidates as unprepared. The question is whether Palin is facing more scrutiny because of sexism. I don't see any evidence of this.
The Saturday Night Live skit? These charges of sexism are just silliness.
I don't see any story here. Palin is being treated on all levels as a national political figure (only she is has much more protected than most).
This sexism thing with Palin is nothing more than a distraction from the fact that she is completely unprepared.