A landmark US court ruling on birthright citizenship is coming. What does NZ law say?
- Written by: Guy C. Charlton, Associate Professor, School of Law, University of New England
The US Supreme Court is poised to deliver its much anticipated and debated decision on the question of birthright citizenship.
At the centre of the case (known as Trump v. Barbara) is an executive order signed by President Donald Trump on his first day of office in 2025, barring citizenship for children born to parents illegally in the United States or on long-term visas.
Americans have long held that the 14th Amendment to the Constitution grants automatic citizenship for babies born on US soil. Trump disagrees.
The case is also one more example of how citizenship and residency in many countries – including New Zealand – has become an increasingly vexatious issue in an age of massive migration.
Constitutional challenge
The 14th Amendment, passed after the American Civil War, states:
All persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States and of the State wherein they reside.
A decisive case in 1898 largely established that babies born in the US are legally citizens. But the Trump administration argued the 14th Amendment only applied to former slaves.
That would mean babies born to individuals who are not “domiciled” – thus not owing allegiance to the US – are not citizens under the amendment.
Solicitor General D. John Sauer argued the reinterpretation was justified given the threat of unchecked immigration and “birth tourism”.
At this stage, a majority of the Supreme Court seems sceptical about the Trump administration’s argument.
But from a broader perspective, Trump v. Barbara is also an increasingly common example of how citizenship and migration disputes are challenging constitutional understandings and legal recognition of national, social and individual identity.
Belonging and connection
Citizenship is essentially about relationships and connections – to people and place.
Formal legal membership of a nation-state is primarily identified at birth, either by parentage (known in law as jus sanguinis or “right of blood”) or from the place where one is born (jus soli or “right of the soil”).
Either way, citizenship provides certain core protections for the holder, including the right to remain in a country without fear of removal.
The English common law followed the jus soli approach, meaning nearly every person born within countries such as New Zealand and the US were considered citizens.
Like the US, New Zealand followed the jus soli approach from 1948 to 2005, when it moved to a hybrid form of jus sanguinus. This aligned the country with Australia and the United Kingdom, which restrict automatic citizenship based on parental status.
Today, a person born in New Zealand to parents born elsewhere does not automatically become a citizen.
The change increased the likelihood of creating undocumented, native-born residents who are still not citizens. If a government alters definitions of immigration status, it can affect education and employment rights.
This has the potential to create a permanent underclass of non-citizen residents, as is the case in some European countries.
Indeed, questions of belonging and connection surround the pending Immigration (Enhanced Risk Management) Amendment Bill. This makes targeted amendments to the Immigration Act 2009 and is now making its way through the New Zealand parliament.
As a mechanism to remove criminals or unwanted aliens, it seeks to expand the state’s power to expel long-term residents up to 20 years after they gained residency.
The Treaty and citizenship
The Waitangi Tribunal considered questions of citizenship in its 2025 report He Tangata, he Whenua. While it didn’t explicitly consider the question of birthright citizenship, the report did consider what community membership means in the context of Māori identity.
The tribunal examined the claim of John Ruddock, a Māori born in Australia who became a New Zealand citizen by descent, but whose Australian-born children were not eligible for automatic New Zealand citizenship under the Citizenship Act 1977.
The act limits citizenship by descent to one generation. When Ruddock moved back to New Zealand, he discovered his children had no legal right to remain. He argued their special relationship with the country as tangata whenua (indigenous, people of the land) – recognised by the Treaty of Waitangi – was wrongly excluded in the law.
The report addresses how the act fails to recognise Māori as tangata whenua and fails to incorporate concepts such as whakapapa (genealogy) and ahi kā (continuous occupation).
By creating a system that prejudices Māori living abroad, the tribunal said, the Crown breached Article 3 of te Tiriti o Waitangi, which guaranteed Māori the “rights and privileges of British subjects”. It noted that citizenship is the core mechanism by which “a community is imagined through the practice of granting nationality”.
In the US, citizenship was given special constitutional protection to address the historical and social legacy of slavery.
By contrast, New Zealand’s colonial history and political development (including the Treaty of Waitangi), have meant citizenship has not been seen as requiring special legal protections.
But the Waitangi Tribunal report and the proposed amendments to the Immigration Act suggest there are unresolved questions about citizenship and individual connection to Aotearoa New Zealand.
And how can Maori sensibilities and identities be reconciled with purely Western notions of citizenship and national identity?
How can notions of national identity and citizenship be insulated from legal changes based on short-term political calculations or careless lawmaking?
Perhaps the pending birthright ruling from the US Supreme Court provides an opportunity to forge a concept of citizenship that aligns with New Zealand’s unique histories of relationship and belonging.
Authors: Guy C. Charlton, Associate Professor, School of Law, University of New England
