The U.S. Supreme Court will decide if Trump's order restricting birthright citizenship is constitutional. How many people gain citizenship this way?

Justice Samuel Alito invoked an analogy from the late Justice Antonin Scalia on Wednesday as the Supreme Court weighed whether birthright citizenship extended to children of illegal immigrants.

Solicitor General John Sauer was caught off-guard when Gorsuch, a conservative justice appointed by Trump in the president’s first term, asked him whether native Americans are birthright citizens under the administration’s argument. “I think so? I mean, obviously, they’re granted citizenship by statute,” Sauer said before Gorsuch interrupted him.