This is one of the most insightful pieces of analysis on McCain's ploy and why it might work. Essentially, it argues that McCain is trying to change the conversation from who is the most qualified and has the better answers to who has the right values. Ultimately, the article argues it is through cultural narratives, metaphors, and frames that we understand and express our ideals. Sarah Palin upends Obama and Biden's appeal to family values and blue collar ideals, by putting a truly woman of the people. It also puts a person with truly Western conservative ideals, putting Obama's Western strategy at risk.
There is early evidence at Rassmussen report that Palin is generating the type of enthusiasm and lift for McCain that he must have hoped for. The question is, will this survive an intense scrutiny of Palin.
It'll be interesting to see how Obama and Co. respond.