Maybe she is on the ticket for only one reason.
No, it's not because she's a woman.
Nor is it because she's not a woman.
Nor is it because she hasn't had an abortion.
Maybe she's on the ticket to act as "live bait" to Democrats.
Maybe Senator John McCain (R-AZ) was sitting around thinking to himself one day and this is what he thought.
"Hey, I'm having no luck pointing out Senator Barack Obama's (D-IL) lack of experience. The message isn't getting out.
Maybe if I put Governor Sarah Palin (R-AK) on the ticket, the Democrats will talk about her experience and that will give me the opening I need to talk about his.
I'm also not having much luck going after his lack of reformer credentials. She has some reformer creds on that whole 'bridge to nowhere' thing. If I put her on the ticket, maybe they'll go after that and then I can point out that they never voted against it, even to help victims of Katrina.
Maybe by putting a woman on the ticket, I can get the liberals and the media to use sexist attacks against her, and move more women to my side.
Maybe by putting someone relatively unknown on the ticket, the media will go overboard trying to 'vet' her, and turn into an 'attack machine' with false smears, thus discrediting any future attacks, no matter how valid.
Maybe she can turn the Obama campaign's focus to her and get them off message and forget that they're running against me."
Of course, it probably didn't really happen that way. After all, it'd be pretty silly for anyone to think those things. Most of those "traps" are so obvious that you'd have to be a fool to walk into them.