444 III. VANDERBILTJOURNAL OF TRANSNATIONAL LAW [VOL. 46:443 b. The United States................... 467 EXPANDING STATELESSNESS BY RESTRICTIONS ON BIRTHRIGHT CITIZENSHIP .......................... 484 A. B. C. The U.S. PoliticalLandscape........ ........ 484 BirthrightCitizenship Restrictionsand Statelessness in the United States ............. 492 The Meaning and Consequences of Expanded, MultigenerationalStatelessness ..... 500 IV. CONCLUSION V. APPENDIX.......................................... ............................................. 511 514 I. INTRODUCTION In the United States today, there are an unknown number of persons whom no nation will claim as citizens or nationals. Unless the United States apprehends and attempts to deport these persons, the public is unlikely to know about them, and they are likely to continue to live in the shadows-undocumented both from the perspective of U.S. immigration law and with respect to their countries of origin.' The attempt to control unauthorized immigration by deporting migrants brings this statelessness to light because no country will take them. There are thousands of persons that the United States has been unable to deport in the last several years alone. 2 Many others are also likely to be effectively stateless, given that 12 million unauthorized migrants are thought to be living in the United States today.3 The harm of statelessness, as described below, is significant both to the individual and to the United States. But at present this statelessness at least is limited to one generation, because under existing practices of territorial birthright citizenship, the children of 1. In this Article, I sometimes refer to the class of noncitizens in the United States who lack legal immigration status as "undocumented aliens." This use of the term is not equivalent to "stateless," although as I explain in this Article, an unknown number of undocumented aliens in the United States are effectively stateless. 2. See infra text accompanying notes 190-222 (evidencing the difficulty the United States has faced in deporting migrants). 3. This estimate is based on the Pew Hispanic Center's 2007 study, concluding that as many as 12.5 million undocumented aliens were then in the United States. In 2008, the estimate was 11.2 million. See Julia Preston, Decline Seen in Numbers of People Here Illegally, N.Y. TIMES, July 31, 2008, http://www.nytimes.com/2008/07/31/ us/31immig.html? _r=1&partner=rssnyt (reviewing a report by the Center for Immigration Studies, which argued the decline in immigration was due to increased enforcement efforts).