the Department of Justice issued Circular Letter Number 107 (1909) regarding prosecutorial discretion in immigration-related matters. The letter states: In the opinion of the department, as a general rule, good cause is not shown for the institution of proceedings to cancel certifications of naturalization alleged to have been fraudulently or illegally procured unless some substantial results are to be achieved thereby in the way of betterment of the citizenship of the country. The DOJ’s 1909 guidance was reaffirmed 1976243 and supplemented in an Immigration and Naturalization Service (INS) Special Agent’s Field Manual.244 The manual stated that prior to initiating a denaturalization case, the case “must be reviewed” to determine if “mitigating humanitarian factors are present” and whether “the citizenry as a whole will benefit from such a revocation to a degree that exceeds any possible mitigation.”245 The guidance also emphasized that, “when the holders of illegally obtained papers were themselves victims of deception, and not guilty of any design to break the law,” no action would be taken.246 Political Denaturalization For the first 50 years after the 1906 Act, denaturalization policy and practice focused increasingly on naturalized citizens’ political allegiance in the form of membership in suspect groups, especially those considered to espouse communism.247 Procedurally, these cases alleged illegal procurement of naturalization, for failure to meet the “attachment” requirement regarding allegiance to the Constitution.248 As a matter of policy, denaturalization “became a means of cleansing the body politic.”249 Between 1907 and 1948, an average of approximately 462 denaturalization cases were brought each year.250 The most significant legislative change made during this period was the enactment of the 1940 Nationality Act, which added the “good moral character” and “attachment” requirements for naturalization, paving the way for denaturalization based on the applicant’s political beliefs.251 In 1942, Attorney General Francis Biddle established a denaturalization program to systematically “study cases of disloyalty among naturalized citizens,” calling denaturalization “an important weapon” to root out citizens with suspect political beliefs.252 During World War II, the popular joining of political belief and ethnic identity resulted in the internment of Japanese Americans (including the native-born), rampant expatriation of native-born citizens,253 and denaturalization on grounds of disloyalty or “subversive activities.”254 Later amendments to the legal framework responded directly to concerns about the scale of denaturalizations and political motivations for them during this time.255 The 1952 Immigration and Nationality Act, which contains the current formulation of the denaturalization statutes, was drafted during the era of the “Red Scare,” a time when the U.S. government was intensely focused on communist activities. In 1950, “the Department of Justice embarked on a full-scale 62 UNMAKING AMERICANS