The acclaimed journalist and bestselling author Daniel Okrent is our guest; he tells us about his new book, "The Guarded Gate: Bigotry, Eugenics, and the Law That Kept Two Generations of Jews, Italians, and Other European Immigrants Out of America." This book looks back to the 1920s is reveal a dark and forgotten chapter of American history -- a troubling era with serious implications for the present day. "The Guarded Gate" tells the story of the scientists who argued that certain nationalities were inherently inferior, thus providing the intellectual justification for the harshest immigration law in American history. Brandished by various upper class Bostonians and New Yorkers -- many of them (surprisingly) progressives -- who led the anti-immigration movement, these eugenic (and pseudo-scientific) arguments helped keep hundreds of thousands of Jews, Italians, and other unwanted groups out of the U.S. for 40+ years. Per Kirkus Reviews: "[This is] a frighteningly timely book about a particularly ugly period in American history, a bigotry-riddled chapter many thought was closed but that shows recent signs of reopening.... One of the narrative's great strengths is the author's inclusion of dozens of minibiographies illuminating the backgrounds of the racist politicians and the promoters of phony eugenics 'research'....[A] revelatory and necessary historical account."