WASHINGTON (AP) — The U.S. Supreme Court is hearing arguments at 10 a.m. ET over the constitutionality of President Donald Trump’s order to end birthright citizenship for children born in the United States to someone in the country illegally or temporarily.

The birthright citizenship order, which Trump signed on Jan. 20, 2025, the first day of his second term, is part of his Republican administration’s broad immigration crackdown.

Trump plans to be in attendance. He will be the first sitting president to attend oral arguments at the nation’s highest court.

Every lower court to have considered the issue has found the order illegal and prevented it from taking effect. A definitive ruling by the nation’s highest court is expected by early summer.

Here’s the latest:

Adam Winkler, a constitutional law professor at UCLA, told the The Associated Press that Trump’s attending SCOTUS oral arguments signals how important the president views this case.

However, Trump’s presence “is unlikely to sway the justices,” Winkler said, adding that the SCOTUS justices “pride themselves in their independence, even if some agree with much of Trump’s agenda.”

The fanfare of Trump being in the courtroom will make for a different experience for the justices themselves, however, as “Trump’s presence will make the atmosphere a little bit more circus-like,” Winkler said.

Solicitor General D. John Sauer is making his ninth Supreme Court argument and second in as many weeks. Sauer’s biggest win to date was the presidential immunity decision that spared Trump from being tried for his effort to overturn the 2020 election.

Sauer was a Supreme Court law clerk to Justice Antonin Scalia early in his legal career.

ACLU legal director Cecillia Wang, the child of Chinese immigrants, is presenting her second argument to the Supreme Court. In the first Trump administration, a 5-4 conservative majority ruled against Wang’s clients in another immigration case.

It’s not an April Fool’s joke. Alito was born this day in 1950. Only Thomas, who turns 78 in June, is older than Alito among the nine justices.

In the post-pandemic era, the other justices allow the 77-year-old Thomas, the longest-serving member of the court, to pose a question or two before the free-for-all begins.

In a second round of questioning, the justices ask questions in order of seniority. Chief Justice John Roberts, whose center chair makes him the most senior, gets the first crack.

The justices have routinely gone beyond the allotted time since returning to the courtroom following the Covid-19 pandemic.

A buzzer and the court marshal’s cry, “All rise,” signal the justices’ entrance from behind red curtains. The livestream won’t kick in for several minutes, until after the ceremonial swearing-in of lawyers to the Supreme Court bar.