ABC’s Sunlen Miller, Matt Jaffe, and John Berman Report: The rain pouring down, his jacket off, his white dress-shirt clinging to his body, Barack Obama played to a crowd in a state that hasn’t elected a Democrat since 1964. Obama and his running mate Delaware Sen. Joe Biden took the stage at the University of Mary Washington in Fredericksburg, Va., before a crowd of 10,000 to 20,000 people who had been waiting hours in the mud to see them. The weather in northern Virginia has been awful the last couple of days. And not long after Joe Biden’s introduction, just...