At John McCain's rally in the town of Lee's Summit, Mo., there were more people standing outside than were able to fit inside. That kind of crowd just hadn't been seen at McCain's events before last week's Republican convention. Saturday in Colorado Springs, about 10,000 people waved American flags at McCain's rally in an airport hangar there, and Friday in the town of Cedarburg, Wis., there were more people crowding the main street and the surrounding blocks than the population of the tiny town. These numbers seemed unfathomable to the campaign just last month. So what happened? Two words: Sarah...