Denaturalization statutes provide ample loopholes for those with an anti-immigrant agenda to undermine naturalized citizenship, rendering it widely contingent and insecure. Echoing a trend in many affluent Western countries, since the early 2000s, the United States has quietly expanded its use of denaturalization proceedings. In the United States, the rise in denaturalization is driven by other prominent socio-legal trends explored in depth throughout this chapter, including: • the expanding use of insufficiently understood or regulated new technologies designed to verify and track identities across government bureaucracies; • the systemic convergence of criminal and immigration law in the country; and • in particular under the current administration, the erosion of certain normative principles that have previously safeguarded the basic blueprint of the American political community. The government programs and policies under review in this chapter span different presidential administrations. Denaturalization, biometric data collection and analysis, and critiques of the U.S. criminal and immigration systems are not new. This report seeks to present comprehensive and accurate information on a field of law that is obscure to most Americans and widely acknowledged by experts to be challenging in practice. Under the Trump administration, the number of denaturalization cases rose significantly in 2017 and 2018, with attendant problems of selected targeting of certain groups, the potential creation of second-class citizens, and the prospect of statelessness. More concerning still is the likelihood that attempted denaturalizations will continue to increase while Trump remains in office. As the case studies of the Dominican Republic and the United Kingdom (and many other historical and contemporary comparative examples) show, once citizenship deprivation is considered as a tool for enforcement of immigration and criminal law, the vulnerability of targeted communities generally expands as practices become more normalized and entrenched in law and state institutions. The increase in the number of denaturalization cases under the period of review is not surprising, as this is the explicit aim of Operation Second Look, and was a foreseeable outcome of Operation Janus. The findings, elaborated in more detail below, also show other patterns that confirm concerns regarding specific groups affected by denaturalization under the Trump administration and the wider impact this is likely to have on immigrant communities. In other words, some of the same communities that President Trump has singled out for exclusion from the American political landscape are disproportionately represented among the targets of denaturalization cases in 2017 and 2018. There is, moreover, no stated end point for this operation, although it has been suggested by the former director of USCIS that Operation Second Look might result in “a few thousand” denaturalizations. Such a statement would likely have seemed unthinkable under another administration and runs markedly against the lofty language of Supreme Court cases strictly constraining Congress’s power to deprive nationality under the Fourteenth Amendment’s Citizenship Clause, which covers naturalized Americans. 44 UNMAKING AMERICANS