Donald Trump wants to scrap birthright citizenship. The Wong Kim Ark Chinese legal case from 1898 complicates it

US President Donald Trump’s assertion that he can unilaterally end birthright US citizenship is likely to meet stiff resistance in the courts.

The Supreme Court said 120 years ago that, with few exceptions, the Constitution automatically grants citizenship to children born in the US even if their parents aren’t citizens.

Although a handful of legal experts say Congress could pass a law to change that rule, that’s a far cry from the president’s assertion in an interview with Axios on HBO that he can do it by executive order.

“There’s an active academic debate over whether mere legislation could change it with respect to illegal immigrants and tourists – probably not, though there are good arguments on both sides,” said Ilya Shapiro, a senior fellow at the libertarian Cato Institute.

“But regardless, it’s not something that can be done by executive action alone.”

The issue turns on the Constitution’s 14th Amendment, enacted after the Civil War to protect the rights of newly freed slaves.

The amendment confers citizenship on anyone who is born in the US and is “subject to the jurisdiction thereof.”

The issue of birthright citizenship has come before the Supreme Court previously, most notably in an 1898 case “United States v. Wong Kim Ark”.

‘It’s ridiculous and it has to end’: Trump threatens to scrap automatic citizenship for children of foreigners born in US

Wong Kim Ark was born in California in 1873 to parents who had come to the United States from China.

After a visit to China, Wong Kim Ark was denied re-entry into the United States in 1895 under the Chinese Exclusion Acts.

The Supreme Court ruled, however, that the acts did not apply to Wong Kim Ark and that he was a US citizen by virtue of being born in the United States.

Citing “the ancient and fundamental rule of citizenship by birth within the territory,” the court said the provision covered “all children here born of resident aliens”, except for American Indians, diplomats and members of invading armies.

That ruling didn’t directly address people who entered the country illegally, but the court touched on that subject in a 1982 ruling that required school districts to enrol unauthorised immigrants.

In a footnote, the court said “no plausible distinction” could be drawn to disqualify the children of undocumented immigrants from the birthright citizenship provision.

Some prominent conservatives say that, barring a constitutional amendment, the issue is settled.

James Ho, now a Trump-appointed federal appeals court judge, wrote in 2011 that the wording of the 14th Amendment leaves no doubt that the children of undocumented residents are covered.

“The plain meaning of this language is clear,” wrote Ho, who at the time was the solicitor general of Texas.

“A foreign national living in the United States is ‘subject to the jurisdiction thereof’ because he is legally required to obey US law.”

John Yoo, a former official in President George W. Bush’s Justice Department, offered a similar assessment last week.

“According to the best reading of its text, structure and history, anyone born on American territory, no matter their national origin, ethnicity or station in life, is an American citizen,” Yoo wrote for the American Enterprise Institute.

House Speaker Paul Ryan said Tuesday the 14th Amendment is “pretty clear” in its coverage of undocumented immigrants.

“You cannot end birthright citizenship with an executive order,” Ryan said.

Even if the 14th Amendment were read to not cover the children of undocumented immigrants, Congress would need to change the federal law that was written to codify the conventional understanding, said Michael Dorf, constitutional law professor at Cornell Law School.

Currently, “even if the Constitution would permit Congress to strip such persons of citizenship, it would not permit the president to do so, because that would be contrary to the statute,” Dorf said.

University of Virginia law professor Saikrishna Prakash said language in earlier Supreme Court decisions could help Trump make the case that undocumented immigrants aren’t “subject to the jurisdiction” of the United States. But Prakash said Trump can’t change the conventional understanding on his own.

Trump “can’t just decide who is a birthright citizen,” he said.

“Those people who believe that they qualify for it are going to get an adjudication from the courts.”

Even one of the leading advocates of reinterpreting the 14th Amendment, Yale Law School Professor Peter Schuck, said Trump’s idea for an executive order was off base.

“Trump clearly cannot do so by EO – and I feel confident that no competent lawyer would advise him otherwise,” said Schuck, who co-wrote a 1985 book on the issue.

“This is just pre-election politics and misrepresentation and should be sharply criticised as such.”

Additional reporting by Agence France-Presse