The Supreme Court is taking up one of the term's most consequential cases, President Donald Trump's executive order on birthright citizenship declaring that children born to parents who are in the United States illegally or temporarily are not American citizens, and he was in the courtroom on Wednesday to attend the arguments.

The justices will hear Trump's appeal of a lower-court ruling from New Hampshire that struck down the citizenship restrictions, one of several courts that have blocked them. They have not taken effect anywhere in the country.

Trump is the first sitting president to attend oral arguments at the nation's highest court. Crowds watched from the sidewalks as his motorcade drove along Constitution and Independence Avenues, passing the Washington Monument and the National Mall on the way to the court building.

The case frames another test of Trump's assertions of executive power that defy long-standing precedent for a court that has largely ruled in the president's favor — but with some notable exceptions that Trump has responded to with starkly personal criticisms of the justices. A definitive ruling is expected by early summer.

The birthright citizenship order, which Trump signed the first day of his second term, is part of his Republican administration's broad immigration crackdown.

Birthright citizenship is the first Trump immigration-related policy to reach the court for a final ruling. The justices previously struck down global tariffs Trump had imposed under an emergency powers law that had never been used that way.

Trump reacted furiously to the late February tariffs decision, saying he was ashamed of the justices who ruled against him and calling them unpatriotic.

He issued a preemptive broadside against the court on Sunday on his Truth Social platform. "Birthright Citizenship is not about rich people from China, and the rest of the World, who want their children, and hundreds of thousands more, FOR PAY, to ridiculously become citizens of the United States of America. It is about the BABIES OF SLAVES!," the president wrote. "Dumb Judges and Justices will not a great Country make!"

Trump's order would upend the long-standing view that the Constitution's 14th Amendment, ratified in 1868, and federal law since 1940 confer citizenship on everyone born on American soil, with narrow exceptions for the children of foreign diplomats and those born to a foreign occupying force.

A federal judge has ruled in favor of artificial intelligence company Anthropic in temporarily blocking the Pentagon from labeling the company as a supply chain risk.

U.S. District Judge Rita Lin on Thursday said she was also blocking enforcement of President Donald Trump's social media directive ordering all federal agencies to stop using Anthropic and its chatbot Claude.

Lin said the "broad punitive measures" taken against the AI company by the Trump administration and Defense Secretary Pete Hegseth appeared arbitrary, capricious and could "cripple Anthropic," particularly Hegseth's use of a rare military authority that's previously been directed at foreign adversaries.

"Nothing in the governing statute supports the Orwellian notion that an American company may be branded a potential adversary and saboteur of the U.S. for expressing disagreement with the government," Lin wrote.

Lin's ruling followed a 90-minute hearing in San Francisco federal court on Tuesday at which Lin questioned why the Trump administration took the extraordinary step of punishing Anthropic after negotiations over a defense contract went sour over the company's attempt to prevent its AI technology from being deployed in fully autonomous weapons or surveillance of Americans.

Anthropic had asked Lin to issue an emergency order to remove a stigma that the company alleges was unjustifiably applied as part of an "unlawful campaign of retaliation" that provoked the San Francisco-based company to sue the Trump administration earlier this month. The Pentagon had argued that it should be able to use Claude in any way it deems lawful.

Lin said her ruling was not about that public policy debate but about the government's actions in response to it.

"If the concern is the integrity of the operational chain of command, the Department of War could just stop using Claude. Instead, these measures appear designed to punish Anthropic," Lin wrote.

Anthropic has also filed a separate and more narrow case that is still pending in the federal appeals court in Washington, D.C. That case involves a different rule the Pentagon is using to try to declare Anthropic a supply chain risk.