YOUNGSTOWN, Ohio -- Mayor George McKelvey doesn’t know why he was invited to dinner by President Bush, but described the occasion as successful, “humbling” and a “life-altering experience.” But leading Democrats in the Mahoning Valley find the whole episode amusing, a lesson in Electoral College politics and how the “poaching” game is played. McKelvey, a lifelong Democrat, and his wife attended the White House dinner Wednesday night and the mayor was seated next to the president, according to local broadcast reports. The Youngstown mayor’s dinner with the president followed Bush’s trip Tuesday to the city to promote his community health-center...