Book excerpt: In the years of cultural and political ferment following World War II, a new generation of Jewish- American writers and thinkers arose to make an indelible mark on American culture. Commentary was their magazine; the place where they and other politically sympathetic intellectuals -- Hannah Arendt, Saul Bellow, Lionel Trilling, Alfred Kazin, James Baldwin, Bernard Malamud, Philip Roth, Cynthia Ozick and many others -- shared new work, explored ideas, and argued with each other. Founded by the offspring of immigrants, Commentary began life as a voice for the marginalized and a feisty advocate for civil rights and economic justice. But just as American culture moved in its direction, it began -- inexplicably to some -- to veer right, becoming the voice of neoconservativism and defender of the powerful. This lively history, based on unprecedented access to the magazine's archives and dozens of original interviews, provocatively explains that shift while recreating the atmosphere of some of the most exciting decades in American intellectual life.