On​ 18 January, ten vans of immigration agents carrying rifles and riot shields descended on Columbia Heights, a suburb of Minneapolis. At the home of ChingLy ‘Scott’ Thao, a US citizen, they knocked quickly before shattering the front door with a battering ram. They yanked Thao, who was wearing only bright blue boxers and Crocs, out into the sub-zero cold and bundled him into a black SUV. For about an hour he was driven around and questioned before being deposited back at home without apology or explanation. Less fortunate was another Twin Cities resident, an autistic woman called Aliya Rahman. Five days before Thao’s arrest, Rahman was driving to an appointment at the Hennepin County Traumatic Brain Injury Centre when she was caught up in a traffic jam caused by ICE and her car ended up blocking an intersection. Rahman, who was born and grew up in northern Wisconsin, was told to move her car out of the way. An agent then smashed the passenger-side window, showering her with glass, sliced off her seatbelt with a large knife and dragged her out of the vehicle, tearing her rotator cuff. A few weeks later, Rahman accompanied her representative in Congress, Ilhan Omar, to Trump’s State of the Union address, and again needed to be treated in hospital after being arrested for standing up during the speech.

The executive order handed down on the day of Trump’s second inauguration described his immigration policy as animated by the goal of ‘total and efficient’ removal of ‘illegal aliens’ from the United States. As the treatment of Thao and Rahman suggests, one of the many problems with the programme is that ICE has no simple way to distinguish reliably between US citizens and the roughly fourteen million undocumented people living in the United States. In any case, neither ICE agents nor the state police who work alongside them seem all that worried about these distinctions. Kenny Laynez-Ambrosio, an 18-year-old US citizen who lives in West Palm Beach, Florida, was stopped last May by highway patrol. As soon as the other two male passengers in the pickup truck his mother was driving were flagged as undocumented, Laynez-Ambrosio was dragged out of the vehicle with them (they used a stun gun on one of the other men), arrested and transferred to ICE. When he claimed truthfully that he was a US citizen, one of the troopers replied: ‘You’ve got no rights here. You’re illegal brother.’ A few months later, the US Supreme Court affirmed as ‘common sense’ the legal rule that police and ICE can make immigration stops partly taking into account skin colour, complexion or accent.

It’s hard to know just how many US citizens have been swept up in immigration enforcement given the Trump administration’s reluctance to concede error. Between January and October 2025, by one count, 170 US citizens were detained. Not all of them were released like Thao, Rahman and Laynez-Ambrosio. A lawsuit was filed in Louisiana last July on behalf of several children between the ages of two and eleven who are US citizens but were unlawfully deported along with their non-citizen guardians. One of the children, the complaint noted, has stage four cancer. The tally of the erroneously detained and deported is likely to go on rising. ICE’s 2025 budget was $28.7 billion, over three times its Biden-era figure and more than Brazil or Spain spends on its army. Even with the best intentions in the world, tripling the size of a law enforcement body will bring problems. Finding high-quality recruits will be a particular challenge, and there’s reason to think ICE’s approach has been simply to stop screening new hires.

Citizens are swept up in immigration enforcement not only as a result of mistaken targeting. The Trump administration has introduced two new policies that aim to turn citizens into migrants who can be expelled. The first, a narrowing of birthright citizenship, has attracted considerable public attention and legal challenges; it seems likely to falter in the courts. The second was announced with less fanfare and is likely to escape judicial checking, which means it will probably be more consequential. It involves stripping naturalised citizens of their US status. It is unlikely to affect as many people as the 540,000 deported in 2025 but even a small number of well-targeted denaturalisations could have far-reaching political effects.

Among his inauguration-day announcements, Trump issued an executive order seeking to redefine the US constitution’s grant of ‘birthright citizenship’. Until 1868, the constitution was silent on who was a citizen, instead delegating authority to Congress to ‘establish a uniform rule of naturalisation’. Flexing this power in 1790, it invited ‘any free white person’ of ‘good character’ to naturalise. The tens of thousands of men, women and children dragged to North America by the triangular Atlantic trade were not included in this offer and those born of enslaved parents in the United States stood on equivocal legal ground for more than half a century. In 1857, in Dred Scott v. Sandford, the plaintiff challenged his and his family’s bondage. Scott pointed to a principle of the common law, enshrined by Lord Mansfield in 1772, which held that when a slave was transported onto free soil, his enslavement ended. The chief justice, Roger Taney, and a majority of the court didn’t embrace that principle in their judgment. Any court needs jurisdiction to decide a case, Taney reasoned, and Scott’s plea hinged on a jurisdictional provision that covered cases between one citizen and another. But Scott, Taney argued, wasn’t a citizen. Those ‘whose ancestors were imported into this country, and sold as slaves’ were not ‘included, and were not intended to be included, under the word “citizens” in the constitution’. Taney’s logic, impeccable on this point, is an example of the theory of legal interpretation known as originalism, which dominates the contemporary court.

After the Civil War, Congress repudiated aspects of the antebellum racial order in a series of constitutional amendments. In the Senate debates over what became the Fourteenth Amendment of 1868, Senator Lyman Trumball proposed that citizenship should flow to anyone ‘born in the United States’. When Democratic and Republican senators objected that this might sweep Native Americans into the polity, the caveat ‘and subject to the jurisdiction thereof’ was added. To this day, a member of a Native American tribe is not a citizen by force of the basic law but at the sufferance of Congress. It took legislators more than half a century to extend citizenship to tribal members (in the Indian Citizenship Act of 1924), and that entitlement could be undone today by a majority vote in Congress.

Trump’s birthright citizenship order leverages the evasive generality of the term ‘subject to the jurisdiction thereof’. The order denies birthright citizenship to children whose mothers were ‘unlawfully present in the United States’, or whose presence is ‘lawful but temporary’, at the time of their birth. In part this recreates the regime that the Fourteenth Amendment tried to change. An enslaved woman in 1858 was not considered a citizen; she had ‘lawful, but temporary’ presence. If the Trump order were applied to her children, they would not be citizens by birth.

Every federal trial court and court of appeal that has heard a challenge to the birthright citizenship order has found it devoid of a legal basis. The fact that it makes an obvious mockery of the amendment’s ‘original’ meaning might lead one to expect that the Supreme Court will follow suit when it hears the case on 1 April. The justices, however, have shown little interest in original meanings when they don’t chime with their immediate political aims. The government seems likely to lose the birthright citizenship case, but that outcome is far from certain.

The second part of Trump’s assault on the wrong sorts of citizen has received less public attention and may not be properly tested in court before its rollout. In December 2025, the Department of Homeland Security instructed its regional field offices to ‘supply the Office of Immigration Litigation with 100-200 denaturalisation cases per month’. The DHS also sent denaturalisation experts to its field offices, reassigning staff to help them. These immigration officers cannot on their own strip a person of citizenship. Cases are referred to the Justice Department, whose attorneys decide between civil and criminal denaturalisation suits. The department has said it will ‘prioritise and maximally pursue denaturalisation proceedings in all cases permitted by law and supported by the evidence’. To meet the White House quotas it seems likely that the procedurally more nimble civil action will need to be used.

It is difficult to find any power of denaturalisation in the constitution. Congress is granted authority only to make a ‘rule of naturalisation’, not its inverse. Trumball’s addition to the Fourteenth Amendment – that ‘all persons born or naturalised in the United States … are citizens of the United States’ – is hard to square with denaturalisation. The sentence declares clearly the qualifications for citizenship, brooking no second-guessing or difference in treatment between the native-born and the naturalised.

In practice, denaturalisation was unknown until the early 20th century. When Congress passed the first statutory denaturalisation provisions in 1906 and 1907, it was acting in the context of immigration law that linked citizenship to a particular view of equality in marriage. Since 1855, an American man marrying a non-American woman could pass on his citizenship to her, at least if she was a ‘free white person’ of ‘good character’. Whether American women could do the same was less clear. The Expatriation Act of 1907 resolved the ambiguity, directing that American women marrying non-Americans would lose their citizenship. In 1913 Ethel Mackenzie, a wealthy San Francisco suffragist, was turned away from the ballot box because her Scottish husband wasn’t a US citizen. She also lost the legal right to own property in many states, and to pass on American citizenship to her children. Mackenzie had the resources to take her case to the Supreme Court. A unanimous bench, addressing denaturalisation for the first time, ruled against her. Its decision rested on the ‘ancient principle’ that, by marrying, husband and wife ‘merge their identity, and give dominance to the husband’.

A few years after Mackenzie’s loss in court (her husband took US citizenship), Congress relented, at least in part. The 1922 Cable Act allowed white or black women who married foreigners to keep their citizenship, but not if they had married Chinese or Indian men, as Mary Keatinge Morse had. Born in South Carolina and descended from a Quaker family that came to America with William Penn, the founder of the Pennsylvania colony, Morse was another wealthy suffragist and an early patron of the National Association for the Advancement of Coloured People. In 1924 she married Taraknath Das, a leading Indian nationalist, who had become a US citizen in 1914. A year before their marriage, the Supreme Court had ruled that a ‘high-caste Hindu’ could not be naturalised because they were not ‘white’ in common parlance. Das suddenly found himself without citizenship, and Morse in turn lost hers. Writing in the Nation in 1926, she described herself as ‘an American-born woman’ who, by the ‘double standard of the American government … am not only rendered alien, but a stateless alien’. She and her husband moved to Europe, where they remained until 1935.

Sau Ung Loo Chan was born in Hawaii and graduated from Yale Law School in 1928. Returning to the US after a decade in Hong Kong, she was told she had lost her citizenship as a result of her marriage to a Chinese American because her husband could not prove his nationality. She was so successful in marshalling witnesses and evidence of her husband’s status that the immigration service offered her a job. She had previously been denied entry to the US on returning from a trip to Europe after her first year at Yale. ‘I knew just enough law to scream “habeas corpus” at officials,’ she later said. ‘They finally let me in.’

The ideological dissidents who were expelled under denaturalisation provisions that became law in 1906, and were periodically expanded by Congress after that, were less fortunate. The 1906 law allowed the Justice Department to begin denaturalisation proceedings if citizenship had been ‘illegally procured’ – by fraud, say. In practice, according to the historian Patrick Weil, it was ‘quite discretionary’, and invariably ‘highly political’ and ‘symbolic’. In 1940 and 1952, the discretionary power was formalised by provisions permitting denaturalisation for people who had voted in a foreign election, worked for a foreign government or carried out ‘subversive activities’.

The most notorious example of ideological denaturalisation involved the anarchist Emma Goldman. ‘At first I took this case of the US authorities taking away my papers as a joke,’ Goldman wrote, ‘but now it turns out serious; altogether too serious.’ Concerned that targeting Goldman would only add to her reputation, the government focused on Jacob Kersner, the man she had briefly married and then divorced in 1885 after emigrating from Russia. Kersner’s naturalisation was cancelled on the ground that he had been under eighteen when he became a citizen. Since Goldman derived her citizenship from their marriage, she thus lost her citizenship too. In December 1919, she was bundled onto the SS Buford, docked at Gravesend Bay in Brooklyn, which took her and 247 others to the Soviet Union. Denaturalisation was later used against suspected fascists in the 1940s and communists in the 1950s. According to one estimate, more than twenty thousand Americans lost their citizenship between 1907 and 1967.

The Supreme Court eventually curtailed the stripping of citizenship on ideological grounds, although the tactic didn’t entirely disappear from the government’s repertoire. In 1950, Bays Afroyim, a naturalised US citizen, moved to Israel and voted in an election there. When he tried to renew his US passport, he was refused because he had voted in a foreign election. Like Mackenzie, he challenged the decision in court. Unlike her, he won. Only actual ‘fraud in the naturalisation process’, the Supreme Court held, could be a basis for stripping someone’s citizenship.

It was the Obama administration that first broached the possibility of mass denaturalisations on the basis of such fraud. In 2008, Homeland Security identified 206 people who had been ordered to be deported but managed to get citizenship under a different name because their fingerprints had been misfiled. Operation Janus launched criminal and civil actions for fraud and sought the denaturalisation of those responsible, but no one was deported during Obama’s presidency.

The first Trump administration ramped up these efforts. In September 2017, the attorney general, Jeff Sessions, promised that his department would ‘aggressively pursue deportation … to strategically enforce the nation’s immigration laws’. The first victim of this campaign was Baljinder Singh, who had apparently entered the United States under the name Davinder Singh 27 years earlier. The exact facts of Singh’s case are obscure. A civil deportation action does not require the person being stripped of their citizenship to be present in court. Homeland Security posted a notice to Singh’s last known address, delivering it to a person of ‘suitable age and discretion’. There is no way of knowing whether Singh ever received notice of the action challenging his status. Nevertheless, the government’s lawyers were able to secure judgment against him. It’s possible that Singh still does not know he has lost his citizenship. But even if he had appeared in court, he would not have been entitled to an attorney, a jury, or to offer testimony. The absence of a statute of limitations on civil denaturalisation means that a person can lose their citizenship one year, ten years or even fifty years after their citizenship ceremony. It’s easy to see how this authority could be misused.

Last year, after Zohran Mamdani won the Democratic primary for the New York City mayoral election, Andy Ogles, a Tennessee Republican who sits in the House of Representatives, sent the attorney general, Pam Bondi, a letter demanding that she open ‘denaturalisation proceedings’ against Mamdani. Ogles pointed to the rap lyrics Mamdani had written a few years earlier, which Ogles characterised as expressions of solidarity with criminals convicted of terrorism-related offences. Soon afterwards, Trump demanded that the comedian Rosie O’Donnell lose her citizenship because she was ‘not in the best interests of our Great Country … She is a Threat to Humanity.’ There’s no reason to think that either Mamdani or O’Donnell is at risk of losing their US passport. Yet a year ago it wouldn’t have seemed at all likely that James Comey, a former director of the FBI, or Letitia James, the attorney general of New York, or Jerome Powell of the Federal Reserve would be investigated, let alone threatened by a grand jury indictment. The Trump administration is adept at the rapid evisceration of settled legal expectations.