CALIFORNIA - A moment before beginning his dinner, Masab, son of West Bank Hamas leader Sheikh Hassan Yousef, glances at the friend who has accompanied him to the restaurant where we met. They whisper a few words and then say grace, thanking God and Jesus for putting food on their plates. It takes a few seconds to digest this sight: The son of a Hamas MP who is also the most popular figure in that extremist Islamic organization in the West Bank, a young man who assisted his father for years in his political activities, has become a rank-and-file Christian....