"A body of research done over the past five years has consistently shown that the fastest growing segment of the foreign-born population consists of undocumented immigrants (Massey and Bartley, 2005; Passel and Suro, 2005; Passel, 2005). The numbers have risen to such a large degree, that the number of foreign-born who are undocumented rivals those who are here as legal permanent residents."Population Estimates and the Needs of Local Governments [PDF]Joseph J. Salvo Population Division New York City Department of City Planning Warren A. Brown Program on Applied Demographics Cornell Institute for Social and Economic Research Cornell University Paper Presented at the U.S. Census Bureau Conference on â€?Population Estimates:Meeting User Needs,â€? Alexandria, VA, July 19, 2006The period of time in which illegals became the fastest growing segment of the population was what we generally refer to as "The Bush Administration."