Choosing Sarah Palin is a Hail Mary play that shows a sense of desperation that McCain has managed to up until now. She's way inexperienced (less than two years of elected officialdom, and McCain's griping about Obama's inexperience?), she's not going to get him any states that he wasn't getting already (Alaska and Idaho don't get any redder), and she doesn't get him any voters that wouldn't be voting for him anyway (is the pro-life conservative NRA Christian movement really going to vote for Obama?).
Plus, like Jack Kemp and George HW Bush before her, she's running for the VP spot under an ANCIENT candidate. At least with Reagan and Dole, we knew that if they kicked it, their VPs would be up to the task, but can anyone say with a straight face that Palin could handle the presidency when McCain dies (which is more likely than not in the next eight years)?
So, McCain went looking for someone who was a maverick, someone who is a DC outsider, and someone to shore up his conservative base. And now, with two Y chromosomes on the Democratic ticket, McCain thought 'hey, if my VP has boobs, I can get all of those disaffected Hillary voters too!'
The trouble is that those disaffected Hillary voters are starting to realize that despite the hard feelings between Clinton & Obama, a vote for Obama is way more like a vote for Hillary than a vote for McCain is.
Poor John McCain.