ABC News' Matthew Jaffe Reports: As Election Day looms just over two weeks away, Sen. Joe Biden, D-Del., said Saturday that with Republicans firing "vicious" and "dangerous" attacks at Sen. Barack Obama, D-Ill., voters are "having a difficult time" opting for the man who would become the nation's first African American president. "Undecided people are having a difficult time just culturally making the change, making the move for the first African American president in the history of the United States of America," the Democratic vice-presidential nominee said at a San Francisco fundraiser Saturday evening. "So we need to respond. We...