Changes in federal statutory policy, state criminal justice laws, and federal enforcement initiatives have led to an inflexible and zero tolerance immigration policy with respect to minor drug use. This Article traces the evolution of the statutory scheme and how various provisions in state and federal law interact to create the current policy. It proceeds to investigate the broad reach of these rules if they are fully enforced, in light of the widespread lifetime experience with minor drug use both in the United States and abroad. Drawing on the experience of law enforcement agencies that have abandoned similarly rigid rules, the Article proposes changes to the immigration law that would better reflect societal standards with respect to the appropriate lifetime consequences of past drug use. Finally, the Article argues that more systemic reform depends on developing mechanisms that will better insulate the specific criteria for denying admission from the one-way political ratchet of episodic congressional oversight.