Donald Trump promised mass deportation, campaigning against undocumented immigrants as a scapegoat for Americans’ economic woes, crime concerns, and more. But since taking office, the President has expressed openness to deporting not just undocumented immigrants but U.S. citizens too.
When asked earlier this week whether he’d deport his former advisor, tech billionaire Elon Musk, amid Musk’s criticisms of the “Big Beautiful Bill,” Trump said “we’ll have to take a look.” Musk, who was born in South Africa, became a U.S. citizen in 2002.
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Later the same day, Trump called the citizenship status of New York City’s Democratic mayoral candidate Zohran Mamdani into question, asserting: “A lot of people are saying he’s here illegally. We’re going to look at everything.” Mamdani, who was born in Uganda, became a U.S. citizen in 2018.
Trump also threatened to arrest Mamdani if he interfered with Immigration and Customs Enforcement (ICE) actions, to which Mamdani responded in a statement: “The President of the United States just threatened to have me arrested, stripped of my citizenship, put in a detention camp and deported. Not because I have broken any law but because I will refuse to let ICE terrorize our city.”
The Trump Administration has already pursued policies that strip migrants, including international students and humanitarian parolees, of their visas and legal statuses to be in the country, and it has reportedly deported several U.S.-born children along with their foreign-born parents as it seeks to redefine birthright citizenship.
The President has also repeatedly suggested that U.S. citizens who are convicted of violent crimes should be deported to foreign prisons.
“We’ll have to find that out legally. I’m just saying if we had the legal right to do it, I would do it in a heartbeat,” Trump told reporters on Tuesday. “I don’t know if we do or not, we’re looking at that right now.”
Legal experts have said that deporting U.S. citizens for any reason is unconstitutional, but the Trump Administration appears to be circumventing that restriction by pushing to strip citizenship from certain people, through a process known as denaturalization. While denaturalization can only apply to naturalized citizens, that group is estimated to number more than 25 million, or more than 7% of the U.S. population.
Here’s what to know.
The history of denaturalization
Denaturalization has a long and complex history in the United States.
Patrick Weil, a historian and director of research at the French National Centre for Scientific Research and visiting professor of law at Yale University, wrote a book on it in 2012 called The Sovereign Citizen: Denaturalization and the Origins of the American Republic.
In it, Weil argues that the institution and evolution of denaturalization “made a quiet yet major contribution to the transformation of contemporary American citizenship.”
Through changes in law and Supreme Court rulings, denaturalization went from a process that was broadly used to make the citizenship of foreign-born Americans conditional on their behavior to a rare practice that, because of its high threshold, Weil argues, reifies the near inviolability of U.S. citizenship, naturalized or otherwise.
While Weil outlines a number of laws, court cases, and executive-branch actions that shaped denaturalization over the years, the three main turning points came in 1906, 1940, and 1967.
When the Naturalization Act of 1906 was passed to try to federalize naturalization processes, it included a provision on denaturalization that Weil writes “was originally and primarily conceived as a means of redressing naturalization fraud and illegality committed prior to or during the naturalization process itself—before the moment an alien obtained American citizenship.” In reality, however, in the following decades, most denaturalizations “occurred out of a desire to expel from the body politic ‘un-American’ citizens: most of them not for fraud or illegality committed before they were naturalized, but because of who they were or what they had done after they obtained American citizenship.”
“Denaturalization became a means for cleansing the American body politic of those naturalized citizens who behaved in ways considered un-American, due to their attachment to a ‘foreign’ morality or to their race, land of origin, or political ideas—sometimes before their naturalization, but, most often, developed afterward,” Weil writes. It became “a tool for ridding the American citizenry of ‘undesirables.’”
“If a naturalized citizen was Asian, spoke out against war, was a Socialist, a Communist, or a fascist, or lived abroad, she risked the loss of her American citizenship,” Weil writes, though he noted that: “from 1906 until the end of the 1930s, denaturalizations for political or racial reasons numbered fewer than one hundred. The majority of cases continued to revolve—at a pace of hundreds some years—around foreign-born Americans residing abroad.”
During World War II, denaturalization “became an integral part of a proactive program by the Justice Department to bolster national security against threats from America’s ‘enemies.’”
But “foreign-born Americans were not the only ones at risk,” Weil explained. “When denaturalization became a central part of the government’s national security policy during World War II, the 1940 Nationality Act also expanded the number of American-born citizens subject to automatic loss of citizenship.” Before, only American-born citizens who acquired a foreign citizenship could be subject to denationalization, but the 1940 law “extended the denationalization power to include those Americans who had evaded the draft, joined a foreign army, or participated in foreign elections.”
That’s when “the Supreme Court intervened and began to reduce the scope of the federal government’s denaturalization authority.” Weil writes: “Before the outbreak of war, the Supreme Court had backed the authority of the executive to pursue the denaturalization of new Americans for failing to adhere to a myriad of legal minutiae, from the form of naturalization applications, to the duration of U.S. residence, to the age of their arrival in the United States.” But over the next three decades, it would take up a number of cases relating to denaturalization and denationalization.
“About half of the Court, depending on the particulars of a given case, continued to uphold the authority of Congress to deprive naturalized and native Americans alike of their citizenship. As the basis for its decisions, the Court asserted judicial restraint and the exclusive authority of the elected branches over foreign affairs. The other half of the Court, however, invoked a number of constitutional rights in support of striking down and restricting laws permitting denaturalization and expatriation. Denaturalization had provoked a fierce debate on the Supreme Court between these two factions,” Weil summarizes. “Although intensely divided, the Court progressively reduced the scope of the federal government’s authority to revoke American citizenship. It did so, in part, by upholding free speech and procedural guarantees for foreign-born Americans.”
The most significant ruling came in 1967 when Justice Hugo Black outlined in Afroyim v. Rusk, according to Weil, “an interpretation of the Fourteenth Amendment that secured for all—native-born and naturalized—the full set of privileges entailed in American citizenship. American citizenship was no longer a contingent benefit conferred by a sovereign state in exchange for its citizens’ respect for the laws.”
In the ruling, Black wrote: “The very nature of our free government makes it completely incongruous to have a rule of law under which a group of citizens temporarily in office can deprive another group of citizens of their citizenship.”
Although denaturalization was sharply restricted from that point onward, Weil notes that “a nearly unanimous Court permitted—and still permits, in narrow circumstances—a naturalized citizen to lose her American citizenship.”
The limited criteria for denaturalization
There were around 22,000 denaturalizations in the U.S. before 1967, according to Weil. By the time his book was published in 2012, he said there had been only 150 since, though the Department of Justice would later tell news outlets that there were 305 cases between 1990 and 2017.
“Although its use has been substantially reduced,” Weil wrote, “since 1967 denaturalization is still available on two basic grounds. The first of these grounds applies to individuals who have committed gross violations of human rights.” This primarily focused on naturalized Americans with undisclosed Nazi pasts. “In contrast to judicial skepticism of expatriation in the 1960s and 1970s, courts have not challenged the authority of the government to denaturalize individuals responsible for committing human rights violations,” he adds.
“The second modern ground for denaturalization is for fraud or misrepresentation committed during the naturalization process,” Weil writes.
A 2020 advisory by the Immigrant Legal Resource Center explains that “a naturalized U.S. citizen can have that status taken away if the federal government proves by clear, convincing, and unequivocal evidence in a civil federal court proceeding, or satisfies the beyond a reasonable doubt standard in a comparable criminal case, that the citizen was not qualified for naturalization at the time it was mistakenly granted.”
A naturalized citizen can also be denaturalized, the ILRC says, for “refusing under specified circumstances to testify before a congressional committee on alleged subversive activities,” under a Cold War-era law that remains valid, or for failing to meet the requirements if they were naturalized under the wartime-military-service path to citizenship.
While a criminal revocation of naturalization on the basis of naturalization fraud requires, like in all criminal cases, the government to meet a beyond-a-reasonable-doubt burden-of-proof conviction, civil denaturalization proceedings require the government simply to convince a federal court, in which the defendant may not even be provided with an attorney, that a naturalization was “illegally procured” or “procured by concealment of a material fact or by willful misrepresentation.”
Illegal procurement, according to the ILRC, refers to someone who was ineligible for naturalization but received it anyway and doesn’t require proof of concealment or misrepresentation, though the organization notes that it is largely a distinction without a difference as “procuring naturalization by concealment or willful misrepresentation is also procuring it illegally.”
The eligibility conditions that one can be accused of violating include: a) lawful permanent resident status for five years (or three if married to a U.S. citizen); b) continuous residence in the U.S. for that five- or three-year period; c) physical presence in the U.S. for at least half of that five- or three-year period; d) good moral character; and e) that the person was “ “attached to the principles of the Constitution of the United States, and well-disposed to the good order and happiness of the United States” during that five- or three-year period.
The last two conditions are the most broad and open to interpretation. “Many of the cases for denaturalization based on lack of good moral character involve individuals who have committed crimes prior to naturalization, but were not arrested or charged until sometime after naturalization, and they did not disclose the existence of these crimes during the naturalization application process,” the ILRC writes. Similarly, if within five years after naturalization, someone “ joins or becomes affiliated with an organization that would have precluded naturalization,” such as a terrorist group, they can be presumed to have been “not attached to the principles of the Constitution” and “not well disposed to the good order and happiness of the U.S. at the time of naturalization,” and thus denaturalized.
Denaturalization under Trump
Former President Barack Obama ramped up denaturalization efforts with a Department of Homeland Security program called Operation Janus, mined data, including fingerprint records, to identify people who obtained citizenship through false pretenses.
But the first Operation Janus denaturalization didn’t occur until January 2018, when Trump was in office. U.S. Citizenship and Immigration Services also announced plans around the same time to refer some 1,600 cases to the Justice Department to prosecute, and in its fiscal year 2019 budget, the Department of Homeland Security redirected funds from USCIS to ICE for investigations into naturalized citizens.
Trump’s first-term administration took denaturalization efforts “to new levels,” Cassandra Burke Robertson, a law professor at Case Western Reserve University, wrote in 2019. A factsheet by the Open Justice Initiative said the number of denaturalization cases filed annually under Trump nearly doubled that of Obama.
In 2020, the Justice Department also established in its immigration office a Denaturalization Section “dedicated to investigating and litigating revocation of naturalization,” ostensibly focusing on “terrorists, war criminals, sex offenders, and other fraudsters who illegally obtained naturalization.”
“Despite the significant resources this administration is expending on these cases,” the ILRC noted in its 2020 advisory, “in absolute terms the number of people who have had their citizenship stripped remains small so far. However, there are fears that the creation of the DOJ’s Denaturalization Section may result in many more people being denaturalized in the near future. In addition, these efforts will have a chilling effect on the number of legal permanent residents applying for U.S. citizenship and will further burden a system that is already delayed in adjudicating and granting immigration benefits.”
In 2021, President Joe Biden issued an executive order directing agencies to review denaturalization and passport revocation practices, “to ensure that these authorities are not used excessively or inappropriately.”
But since taking office again, Trump has made denaturalization a priority again.
A June 11 Justice Department memo published online issued guidance to the Civil Division, the largest litigating body of the department, on its priority initiatives, which included the revocation of citizenships.
Assistant Attorney General Brett Shumate, who leads the division, said in the guidance that the division “shall prioritize and maximally pursue denaturalization proceedings in all cases permitted by law and supported by the evidence.”
“The benefits of civil denaturalization,” said Shumate, “include the government’s ability to revoke the citizenship of individuals who engaged in the commission of war crimes, extrajudicial killings, or other serious human rights abuses; to remove naturalized criminals, gang members, or, indeed, any individuals convicted of crimes who pose an ongoing threat to the United States; and to prevent convicted terrorists from returning to U.S. soil or traveling internationally on a U.S. passport.”
Among the cases Shumate ordered prioritizing are cases on those who pose a potential threat to national security, including those with links to terrorism, espionage, or unlawful export from the U.S. of sensitive goods, technology, or information; and those who commit certain kinds of fraud.
The National Association of Criminal Defense Lawyers criticized how the directive calls for denaturalization via civil proceedings, which the advocacy lamented carry “a lower burden of proof” and “do not require the government to provide the accused with an attorney.” It also criticized the memo’s “broad scope and vague language.”
“The Trump Administration’s push to revoke citizenship is alarming, and raises serious Fourteenth Amendment concerns,” said NACDL President Christopher Wellborn. “The use of civil litigation to evade Sixth Amendment obligations demonstrates contempt for the right to counsel. And although the memo purports to target concealment of earlier offenses, the language suggests that any offense, at any time, may be used to justify denaturalization.”
When it comes to Musk and Mamdani, however, legal experts have said denaturalization proceedings are unlikely. “Denaturalisation is limited to cases where the government can prove material fraud in their original applications,” Michael Kagan, a law professor at the University of Nevada in Las Vegas, told Al Jazeera. Trump’s talk of deporting the two, Kagan says, “appears to be irresponsible rhetoric designed to intimidate political opponents.”
Musk has previously denied accusations of working in the country illegally before he became a citizen.
Mamdani has been accused by members of Congress of sympathizing with terrorists. But while former New York City Mayor Rudy Giuliani, who was recently appointed to a Homeland Security advisory council, expressed support for calls to denaturalize and deport him—“I think that is very responsible request and something the government should do given the nature of the things that he says,” Giuliani said last week, calling Mamdani a “traitor”—he caveated: “I don’t know that we can come to the conclusion and convict him of it, but he raises a real legitimate concern that he is not a loyal American.”
As Weil noted in his history of denaturalization, the Supreme Court has affirmed that being “a loyal American” is no longer a condition for U.S. citizenship. But as the history of denaturalization has also shown, the Supreme Court can change its mind. And this Supreme Court has already been observed to show “astounding” deference to Trump.
Still, even if the Trump Administration were to denaturalize Mamdani, which would preclude him from taking office, that wouldn’t necessarily mean it could kick him from the country. Denaturalized citizens do not automatically get deported; rather they are reverted to their last immigration status as a noncitizen—which in Mamdani’s case was a green card holder, or lawful permanent resident.