Our Shadow Immigration System

This chapter explains how legal and institutional developments in immigration enforcement coincided with the dramatic acceleration of illegal immigration during the final third of the twentieth century. Together, these legal and demographic phenomena gave rise to a massive shadow immigration system that today operates alongside the formal immigration regime. This shadow system has rendered Congress’s intricate, detailed code of immigration rules increasingly less central to defining the content and character of the immigrant population. Instead, the Executive’s enforcement judgments—decisions about whom to target from the pool of deportable immigrants—have taken center stage. Indeed, the rise of the shadow system has effectively delegated vast screening authority to the President and other executive branch officials—authority that has culminated in events as dramatic as President Barack Obama’s Deferred Action for Childhood Arrivals (DACA). The large number of unauthorized immigrants living in the United States today amplifies the role of enforcement discretion and further entrenches the shadow immigration system.