Joe Biden only lived in northeastern Pennsylvania for about seven of his 81 years, but the city of Scranton looms large in his autobiography. The city, the state's fourth-largest in the days of the President's youth, was the home of Biden's mother's family for generations, since they immigrated from Ireland in the 19th century. Pennsylvania - and Ireland - make up only about half of the President's family tree but, in his telling, he's Scranton Joe the Irish Democrat through and through.