Believe it or not, journalist and author Thomas Maier has something new to say in a book on the Kennedy family. While they have long been known as America's most prominent Irish Catholic family, no book has focused entirely on that element of the family history. Until now. "The Kennedys: America's Emerald Kings" explores (at great length) how the immigrant experience influenced the family's success, as well as how it would later cope with one tragedy after another. In many ways, this book reads like a metaphor for the Irish immigrant experience itself. Maier did lots of research in Ireland, and it pays off in the early sections on Patrick Kennedy's 1848 trip from Ireland to Brahmin Boston. Inevitably, much of this material is familiar. But the passages on Joe Kennedy's decision not to run for office because he feared America's anti-Catholic bias is eye-opening. Ultimately, Maier (a staff reporter at New York Newsday and author of "Dr. Spock: An American Life") never comes off as one of those authors who is exploiting the Kennedy family. There is a fascinating, five-generation story to tell here, and Maier does it well. ($27.50 / 600 pages / Basic Books)