In a set of cases decided at the end of the nineteenth century, the Supreme Court declared that Congress had "plenary power" to regulate immigration, Indian tribes, and newly acquired territories. Not coincidentally, the groups subject to Congress' plenary power were primarily nonwhite and generally perceived as "uncivilized." The Court left Congress free to craft policies of assimilation, exclusion, paternalism, and domination.

Despite dramatic shifts in constitutional law in the twentieth century, the plenary power case decisions remain largely the controlling law. The Warren...