Over the past four decades, the foreign-born population in the United States has nearly tripled, from about 10 million in 1965 to more than 30 million today. This wave of new Americans comes in disproportionately large numbers from Latin America and Asia, a pattern that is likely to continue in this century. Focusing on the period from 1965 to the year 2020, the contributors tackle the fundamental yet relatively neglected questions, What is the meaning of citizenship, and what is its political relevance? How are immigrants changing our notions of racial and ethnic categorization? How is immigration transforming our understanding of mobilization, participation, and political assimilation? This volume presents a provocative, evidence-based examination of the consequences that these demographic changes might have for the contemporary politics of the United States, as well as for the concerns, categories, and conceptual frameworks we use to study race relations and ethnic politics.