The entire concept of bellweather states, or even counties, is probably going to have to be scrapped eventually due to America being such a mobile country. Once upon a time people pretty much stayed put in one place for most of their lives. Counties and states maintained a character, a feel, a certain make-up that stayed fairly constant over decades. All that changed in the post WW2 years when the suburbs grew and cities shrank. However, even then migration was from city to suburbs and often withing the same county or just one over. In the last five decades all that has changed tremendously.
One big reason why states are changing their voting patterns is that they are now made up of different populations than they used to be.
In addition to that, America is evolving and changing as generations age and replace each other in positions of power and influence. America is not any more the America of 1980 Reagan than it is the America of JFK or LBJ. That ship has sailed.
Various internal crisises have made a majority of people more disposed to government, its power and what it can do for them and the nation.
Regarding Palin: the Obama campaign did NOT have to attack her very much because someone was out there doing far more damage to the Alaskan governor than they could ever hope to do with ads and speeches. The person who most destroyed Sarah Palin was...... Sarah Palin. She completely changed the landscape when she gave those interviews with Charles Gibson of ABC and then Katie Couric of CBS. She showed herself to be intellectually shallow and not well informed about events that a politician in that position should be well informed about. She demonstrated that she was in over her head. She was simply out of her league and did not belong in that position because of her own intellectual and knowledge weaknesses.
Enoough people recognized that and it killed her.
When Tina Fey can get laughs repeating word for word Palins answers in interviews, then you know there is something very very wrong with the candidate herself.
Yes, she is a very attractive person with lots of folksy charm. She did a great job energizing the right wing base of the party and brought in lots of money and people at rallies. But in the end, her own limitations hurt her with the people in the middle that the Party needed to win. If McCain had been a 50 year old man, who knows if people would have let it slide and allowed her to grow into the job as VP? But given his age and health, it was just too big of a chance to take on somebody clearly not up to the task intellectually.
... and this today from Politico.com making the case that it was those at the upper income levels who put Obama over the top
http://www.politico.com/news/stories/1108/15471.html