Nashville -- Speaking to the Tea Party convention here last night, Sarah Palin did not have to deliver a substantive speech built around words and ideas. All she had to do was show up, give her trademark wink and a powerful current of emotion would have passed from her to the crowd of conservatives gathered here. But in a 40-minute, remarkably detailed speech, Palin laid out what could only be described as the framework of a presidential-campaign platform. She ran through a host of specifics about recent failures of national-security and economic policies. And she wrapped it up in a...