The category of social sin elucidates the connection between unjust structures that contribute to undocumented immigration and pervasive ideologies that foster resistance to reform efforts and immigrants themselves. Following an exploration of the development of social sin by Pope John Paul II and Latin American liberation theologians, the author advances a conception of social sin that accounts for its personal, institutional, and nonvoluntary dimensions. The analysis seeks to clarify intersecting levels of inhospitality and injustice.