The freewheeling tactics of his supporters have made the GOP candidate an Internet sensation and an unlikely phenomenon. The late-fall night fairly crackled with energy -- from a persistent Santa Ana wind, the high-tension power lines overhead and, especially, from the crowd packed inside the living room of a ranch house at the west end of the San Gabriel Valley. Eighty people sat elbow to elbow on tight rows of folding chairs, chattering with enthusiasm and ideas. They would produce wall calendars and a concert. They would reenact the Boston Tea Party on the Santa Monica Pier. They would write...