The US supreme court has upheld birthright citizenship, which provides nearly all people born in the country with citizenship, ruling against a central piece of Donald Trump’s anti-immigrant agenda.

“Children born in the United States to parents unlawfully or temporarily present are ‘subject to the jurisdiction’ of the United States and are citizens at birth under the Fourteenth Amendment’s Citizenship Clause,” the ruling says.

Chief Justice John Roberts delivered the opinion. He was joined by the liberal justices Sonia Sotomayor, Elena Kagan and Ketanji Brown Jackson, and the conservative justice Amy Coney Barrett. The conservative justice Brett Kavanaugh concurred with the judgment but dissented in part. The conservative justices Clarence Thomas, Samuel Alito and Neil Gorsuch filed dissenting opinions. The court’s writings in the ruling span 194 pages, nearly 90 of which were written by Thomas in dissent, his longest in his tenure on the court.

Trump called the ruling “too bad for our Country”, but said US Congress should now take up the matter legislatively, suggesting another avenue to keep the issue alive.

“No long and unwieldy Constitutional Amendment is necessary! Congress should start TODAY to work on ending expensive and unfair to our Country, Birthright Citizenship,” Trump wrote on his Truth Social platform. “They will have my Complete and Total Support!”

The president had issued an executive order on the first day of his second term that sought to undo birthright citizenship. The order would override the US constitution, which it cannot do, though his administration has argued the order instead interprets the constitution correctly.

Trump’s order immediately drew lawsuits, including from Democratic state attorneys general and the American Civil Liberties Union. The ACLU argued in front of the US supreme court on the case during oral arguments in April for Trump v Barbara, a class-action challenge to the order, brought by parents of children who would be affected by the change.

Dismantling birthright citizenship is a key facet of Trump’s agenda. He filed an executive order to end it on his first day back in office for his second term. He attended the oral arguments in person when the court heard the case, the first time a sitting president had attended oral arguments.

While the courts deliberated on the case for more than a year, the fate of many thousands of children born in the US to parents without permanent legal status hung in the balance. The order sought to apply the president’s interpretation of citizenship starting on 19 February 2025. The families of those children were part of the lawsuit before the supreme court and noted how the order kept their children’s legal status in limbo.

Civil rights groups and Democrats celebrated the ruling from the conservative court, calling it one of the most important decisions in the modern era and noting how it affirmed the promise of America.

The ACLU, whose national legal director, Cecillia Wang, argued the case before the supreme court, called the decision a “major victory”.

“The court’s decision reaffirms a fundamental American promise – if you are born here, you are a citizen,” Wang said. “A president cannot change the constitution by executive fiat. Our brave clients and our legal team stand with millions of people around our country who spoke up for one of our most cherished rights. The constitution’s guarantee of birthright citizenship stands strong.”

The NAACP, a civil rights group dedicated to advancing the rights of Black people, called the decision a “powerful affirmation of the constitution and the enduring promise of equality it represents”. Voto Latino, a non-profit pushing for Latino voting power, said that “the court drew a permanent line in the sand – defeating a radical attempt to divide our families and strip away any doubt that our community belongs here”. Hakeem Jeffries, the Democratic leader in the US House, noted that the 14th amendment “withstood the unconstitutional attack launched by Donald Trump and his most sycophantic and xenophobic enablers”.

“On the eve of America’s 250th birthday, the far-right Maga conservatives have failed in their quest to remake the United States, and American values have prevailed,” Jeffries said.

Some Republicans have spoken out against the ruling. Mike Johnson, the Republican speaker of the US House, said he was “disappointed”.

“I do think that this has been grossly abused in recent years,” Johnson said at a press conference. “You just come on to the soil and have your child, and then they’re able to avail themselves of the welfare state and everything else.”

The supreme court’s Dred Scott decision in 1857 had ruled Black people were not US citizens, but “a separate class of persons”. But the 14th amendment which reversed the Dred Scott decision, was adopted in 1868 during the Reconstruction era after the US civil war, to codify the rights of Black Americans– and confer citizenship to “all persons born or naturalized in the United States, and subject to the jurisdiction thereof”.

The majority opinion walks through the plain meanings of citizenship, from English common law into slavery and then emancipation, and then into efforts to undermine citizenship, including the Chinese Exclusion Act.

Roberts writes that the “odious” decision in Dred Scott denied citizenship to Black people, arguing then that it was “blood, not soil” that decided citizenship. That was overturned via the 14th amendment, which the court affirmed on Tuesday in upholding birthright citizenship.

“Citizenship, then and now, was the right to have rights – to freely participate in our political community,” the majority opinion says. “The Framers of the Fourteenth Amendment extended that promise to ‘every free-born person in this land.’ We keep that promise today.”

In her concurring opinion, Jackson writes that the 14th amendment’s “universalist aims should forever be the death knell for this kind of claim – one that seeks to make bloodline the marker of birthright”.

“The America that was reborn from the rubble of the Civil War simply does not countenance that inequitable result,” she wrote. “Thankfully, a majority of the Court remembered this today, and has dutifully preserved the most basic animating principle of our Nation’s founding – that all human beings are created equal – once more.”

Thomas writes in his sprawling dissent that Black people were entitled to citizenship because they were Americans with “no other homeland” or allegiance to other nations.

“The same could not be said for the children of foreign temporary visitors,” he writes. “Foreign temporary visitors were attached to their home country, lacked similar bonds to this country, and would not be called upon in time of war.”

Kavanaugh writes in a partial concurrence that he does not believe Trump’s executive order violates the 14th amendment, but that it does violate a federal statute. Congress could, he writes, amend the federal statute or create new legislation to establish exceptions to birthright citizenship for children born to parents who do not have permanent legal status in the country.

“But Congress has not yet done so,” he writes.

Overturning a constitutional amendment requires a two-thirds majority vote of both chambers of Congress, or the legislatures of two-thirds of the states to call for a convention, a much higher bar than passing a new statute. Trump shared an article on Truth Social on Tuesday morning alluding to a statutory process to upend birthright citizenship.

Alito, in his dissent, called the decision “one of the most important” in the court’s history, but, in his estimation, “the Court has made a serious mistake”.

He mentions the idea of “birth tourists”, or women who come to the US solely to give birth to a child in the country and then return home. He believes the 14th amendment grants citizenship solely to those children who “owe allegiance solely to this country” and argues that this interpretation of the law would not require uprooting the lives of children born here to parents not in the country legally. He, like Kavanaugh, floats the idea of Congress addressing the issue.

“Some members of this group have lived here for years, and they have a strong moral claim to be able to remain in the land where they grew up,” Alito writes. “Congress can and should address their situation. The Fourteenth Amendment dictates who must be a citizen, but it does not address who may be a citizen by Act of Congress.”

The Trump administration argued the phrase “subject to the jurisdiction thereof” means babies born in the US to people who are not lawfully present in the country are not citizens. The executive order says this includes when neither of a person’s parents were US citizens or lawful permanent residents, or if a parent has legal, but temporary, status. It sought to apply this meaning starting on 19 February 2025, which would affect hundreds of thousands of babies annually.

D John Sauer, the solicitor general who argued on behalf of the Trump administration, emphasized the concept of “domicile”, saying those who are here unlawfully or temporarily do not have “domicile” in the US or allegiance to the country, unlike the formerly enslaved people the 14th amendment’s citizenship clause applied to.

“Unrestricted birthright citizenship contradicts the practice of the overwhelming majority of modern nations,” Sauer said then. “It demeans the priceless and profound gift of American citizenship.”

Domicile weighed heavily into the Trump administration’s claims, though the word is not included in the 14th amendment. The landmark decision on birthright citizenship, United States v Wong Kim Ark, said that a child born to parents of Chinese descent who had permanent “domicile” in the US would be a US citizen at the time of birth under the 14th amendment. The Trump administration argued “domicile”, meaning a permanent residence, is a critical part of the interpretation.

The justices were skeptical of the government’s claims during oral arguments. Roberts, the conservative chief justice, at one point referred to part of the government’s argument as “very quirky”. Liberal justice Kagan said the government was using “pretty obscure sources” to arrive at part of its case.

In the decision, Roberts wrote that “the Court exhaustively canvassed the text and history of the Citizenship Clause and at no point identified any evidence that the ratifiers thought themselves to be imposing a domicile limitation”.

Roberts repeatedly bats down the idea that “domicile” was much more expansive an idea, and that primary allegiance to the US was commonly seen as part of that definition, both arguments the government tried to make in its case. He writes that “there is scant evidence for this dramatically revisionist view”.

The quest to overturn birthright citizenship has gained steam among some conservatives in recent years, though most legal scholars still believe the amendment has been interpreted correctly. The administration is relying in part on the legal arguments of a white supremacists from the late 1800s, the Washington Post reported. John Eastman, a lawyer who worked with Trump to try to overturn the 2020 election results who has since been disbarred in California, is also a key proponent of the effort to overturn birthright citizenship, Politico reported.

The court has previously ruled against Trump on his broad emergency tariffs. Trump has repeatedly attacked any courts or judges that side against him.

Read more coverage of today’s supreme court rulings:

• US supreme court rules states can exclude trans athletes from female sports

• US supreme court strikes down limit on spending by political parties in support of candidates

• US supreme court upholds birthright citizenship in blow to Trump agenda