The real heart of our national identity is the constant remaking of who and what we are by the countless immigrants who have enriched our culture. One of the core controversies that is engulfing the United States today concerns the very definition of America itself; in particular, the role of religion in public life has engendered intense definition-mongering. Religious conservatives insist that America is "one nation under God," which is often interpreted to mean "a Christian nation." They hold that religion and patriotism go hand in hand and that America has a divine destiny. The Republican Party has virtually...