Culling the Masses is a book of impressive analytical and empirical scope. It consists of truly comparative cross-national research and analysis, examining immigration politics and policy in no fewer than six countries in the Americas: Argentina, Brazil, Canada, Cuba, Mexico, and the United States. It asks important questions about the troubling relationship between racism and democracy. Specifically, it addresses two significant puzzles: why did immigration policy come under the spell of eugenics in the first decades of the twentieth century—and how did an anti-racist turn emerge in later decades, first in the weaker and more authoritarian nations of the Americas before finding its way to the stronger and more liberal-democratic regimes, Canada and the United States? A must read for anyone interested in race, immigration, and democratization.