Bent on curbing unauthorized immigration in the United States, the Department of Homeland Security has implemented Operation Streamline—a program aimed at criminally prosecuting all unauthorized immigrants along a five-mile stretch of the U.S.-Mexico border. While lauded by proponents as a success, Streamline has driven courts to conduct en masse hearings that ultimately compromise immigrant criminal defendants’ due process rights. Although the Ninth Circuit recently held in United States v. Roblero-Solis that these en masse proceedings violate Rule 11 of the Federal Rules of Criminal Procedure, this Article argues that by basing its holding on a procedural rule, Roblero-Solis fails to fully protect the rights of immigrant criminal defendants at the border. To eliminate this problem, this Article calls for courts to base these defendants’ rights on the Constitution and to apply the civil theory of territoriality—and reject the civil doctrines of plenary power and the ascending scale of rights—in criminal proceedings. To help ensure the application of these theories, this Article proposes a system that allows the courts to reduce the number of unauthorized immigrants that it prosecutes and to remedy any violations of the rights of the immigrants that it does.