In The Book of Isaias: A Child of Hispanic Immigrants Seeks His Own America, Daniel Connolly follows Isaias Ramos in his final year of high school and the next two years. He’s a math star at his low-performing Memphis high school — and an undocumented immigrant. Will he go to college? Although he passed a prestigious national calculus test as a junior and his counselors are pushing Harvard, Isaias has doubts. “Why should I go to college?” he asks. “Why? I mean everybody tells