Vice presidential choices aren’t supposed to make much difference. Yet, Sarah Palin’s impact is undeniable and extremely large. Twelve days ago, presidential election futures markets indicated that Barack Obama had a 62 percent probability of winning the election. By Sunday, Obama’s probability had fallen to 46.5 percent, with John McCain at 52.1 percent. With the election at stake and Palin so crucial to the outcome, Democrats have sent “a mini-army of 30 lawyers, investigators and opposition researchers” into Alaska. The media has also understandably descended in large numbers in Alaska. Despite Palin’s name being on the short list of potential...