Washington — A century-plus constitutional guarantee that birth on American soil confers citizenship has survived its most direct legal challenge in generations, after the Supreme Court voted 6-3 Tuesday to strike down President Donald Trump's executive order attempting to curtail birthright citizenship, according to reporting by CBS News and NBC News.

The ruling in Trump v. Barbara marks the second time the high court has invalidated a major initiative from Mr. Trump's current term, following a February decision. The president had signed the birthright citizenship directive on his very first day back in office, framing it as part of a broad immigration crackdown.

Five justices — Chief Justice John Roberts, along with Justices Sonia Sotomayor, Elena Kagan, Amy Coney Barrett and Ketanji Brown Jackson — concluded that the order runs afoul of the 14th Amendment. Justice Brett Kavanaugh, writing separately, reached the same outcome on different grounds, finding the measure inconsistent with federal statute rather than the Constitution itself. Justices Clarence Thomas, Samuel Alito and Neil Gorsuch dissented.

Roberts anchored the majority opinion in the historical meaning of citizenship itself. "Citizenship, then and now, was the right to have rights — to freely participate in our political community. The Framers of the Fourteenth Amendment extended that promise to 'every free-born person in this land,'" he wrote, as quoted by CBS News. "We keep that promise today."

The 14th Amendment's Citizenship Clause provides that "all persons born or naturalized in the United States and subject to the jurisdiction thereof, are citizens of the United States." That language was incorporated into federal immigration statutes twice by Congress — first through the Nationality Act of 1940, and again in the Immigration and Nationality Act of 1952. The Supreme Court had already interpreted the clause in its landmark 1898 ruling United States v. Wong Kim Ark, affirming birth-based citizenship with narrow carve-outs for children of foreign diplomats, occupying armies and, at the time, members of Native American tribes, NPR reported. A 1924 act of Congress extended full citizenship to all Native Americans born in the country.

Had Mr. Trump's order taken effect, it would have stripped automatic citizenship from children born in the United States to parents who are present illegally or on temporary visas — a policy the Migration Policy Institute and Penn State's Population Research Institute estimated would affect roughly 250,000 newborns annually, as cited by CBS News. The administration contended that the Citizenship Clause had been misinterpreted since the mid-20th century and that unrestricted birthright citizenship fuels illegal immigration and birth tourism. Despite those arguments, the order was blocked by every federal court that reviewed it and never took effect.

Legal challenges erupted almost immediately after the directive was signed, with judges in New Hampshire, Washington, Massachusetts and Maryland each halting it on a nationwide basis. The Trump administration appealed those rulings on an emergency basis, but the Supreme Court's initial review was limited to the reach of the lower-court injunctions rather than the underlying constitutional question. A subsequent lawsuit filed in New Hampshire on behalf of children who would have lost citizenship under the policy ultimately brought the merits before the justices.

The case drew unusual attention when Mr. Trump attended oral arguments in April, making him the first sitting president in modern times to observe proceedings at the high court, CBS News reported. Even so, the president had signaled in social media posts over recent months that he was uncertain the court would rule in his favor.

ACLU attorney Cecillia Wang, who argued the case before the justices in April, emphasized the rule's deep roots. "The 14th amendment's fixed bright line rule has contributed to the growth and thriving of our nation," she said, as reported by The Guardian. "It comes from text and history. It is workable and it prevents manipulation."

Writing in dissent, Thomas argued that the 14th Amendment was designed specifically with formerly enslaved Black Americans in mind. "Blacks were entitled to citizenship because they were Americans. They had no other homeland, owed no allegiance to any foreign power, and were subject to no other authority," he wrote, as quoted by NBC News. "The same could not be said for the children of foreign temporary visitors."

This is a developing story.

Informational content only, not legal advice. Consult a licensed immigration attorney.