This Article analyzes changes in the constitutional status of noncitizens in immigration law over the past generation. It shows that notwithstanding the optimistic predictions of scholars, over the last quarter century, with few exceptions, the Supreme Court has been unwilling to impose a constitutional check on the political branches’ immigration policies. Instead, it has reaffirmed and, in some cases, even extended the so-called plenary power doctrine, a doctrine developed to sustain the exclusion of Chinese immigrants in the late 1800s and which effectively removes the entirety of immigration regulation from constitutional scrutiny. The modern Court’s stance toward immigration policies tells a story of rights retrenchment, a scaling back from even the modest gains of the twentieth century. In areas ranging from the right to habeas corpus, procedural due process, discrimination, free speech, and detention, noncitizens today enjoy even fewer constitutional protections than they did at the end of the last century. Far from moving toward a full recognition of the constitutional rights of noncitizens, the modern Court has been moving in the opposite direction.

Importantly, though, these setbacks have not impacted all noncitizens uniformly. Rather, the Supreme Court generally has been willing to recognize at least some constitutional claims raised by lawfully admitted noncitizens, although such willingness has been far from consistent. As to such claims raised by noncitizens present in the U.S. without authorization or noncitizens seeking initial admission, the Court has been decidedly more skeptical. The minimal constitutional protections previously extended to these groups have been jettisoned to a large extent.