Jornal Do Brasilia - Supreme Court to hear landmark citizenship case -- with Trump in audience

Trump's decision to attend the hearing is believed to be unprecedented for a sitting president and will likely be seen as pressuring the justices.

The birthright case is at the heart of Trump's attempts to expand his presidential powers and to restrict immigration.

Trump signed an executive order on his return to the White House decreeing that children born to parents in the United States illegally or on temporary visas would not automatically become US citizens.

Lower courts blocked the move as unconstitutional, ruling that under the Citizenship Clause of the 14th Amendment nearly everyone born on US soil is an American citizen.

The White House said late Tuesday that Trump would be attending the hearing. This is widely believed to be the first time a sitting president has been present for oral arguments at the Supreme Court, let alone in a case brought by his administration.

Trump has spent the first year of his second term asserting extraordinary executive powers, while attempting to sideline Congress and routinely pressuring the courts.

Just a week ago he attacked two of the Supreme Court justices whom he had appointed during his first term because they voted against his tariff policies in another major case. The Republican president also called judges that did not side with him "rogue" and "criminal."

- Born in the USA -

Wednesday's Supreme Court case tests who gets to be a citizen in a country built on immigration.

The constitution says those born on US soil are automatically Americans.

The Trump administration argues that the 14th Amendment, passed in the wake of the 1861-1865 Civil War, addresses the rights to citizenship of former slaves and not the children of undocumented migrants or temporary visitors.

Trump's executive order is premised on the notion that anyone in the United States illegally, or on a visa, is not "subject to the jurisdiction" of the country and therefore excluded from automatic citizenship.

Steven Schwinn, a law professor at the University of Illinois Chicago, said the court is likely to reject the challenge to birthright citizenship.

"This is a court that has looked to history and tradition as a significant guide in understanding the Constitution," Schwinn told AFP. "And it would be a little surprising if, after 150 years, we suddenly discovered we were applying the Citizenship Clause all wrong."

Conservatives have a 6-3 supermajority on the high court and three of the justices were appointed by Trump.

Trump's solicitor general, John Sauer, said that in order to be eligible for citizenship "a person must be both born 'in the United States' and 'subject to the jurisdiction thereof.'"

"Children of temporarily present aliens or illegal aliens are not 'subject to' the United States' 'jurisdiction,'" Sauer said in a brief with the court.

Automatic citizenship for children of undocumented migrants is a "powerful incentive for illegal migration," Sauer said, claiming it encourages "birth tourists."

- 'Dumb judges and justices' -

If the Supreme Court does reject ending birthright citizenship, it would be the second major loss for Trump this term -- the justices struck down most of his global tariffs in February.

Trump called birthright citizenship one of the "great scams of our time" on Tuesday, a day after he took to Truth Social to denounce "dumb judges and justices."

The American Civil Liberties Union, which is defending birthright citizenship before the court, said the Trump administration "is asking for nothing less than a remaking of our Nation's constitutional foundations."

A decision in the case is expected by late June or early July.

J.L. de Oliveira--JDB