House Speaker Mike Johnson said Sunday that Congress must pursue legislation to restrict birthright citizenship following a Supreme Court ruling last week that struck down President Donald Trump's executive order seeking to redefine who qualifies as an American citizen. Speaking on Fox News Sunday, Johnson said Republicans are "looking at all angles" and pledged to advance a bill "immediately" if a viable legislative path exists, while acknowledging that a constitutional amendment would take considerably longer.

The Supreme Court ruled 6-3 in Trump v. Barbara, with Chief Justice John Roberts writing for the majority that children born in the United States satisfy the citizenship clause of the 14th Amendment regardless of their parents' immigration status. Roberts wrote that the framers of the 14th Amendment extended citizenship to "every free-born person in this land" and that the court was keeping that promise. Justice Clarence Thomas, whose dissent Johnson praised on Sunday, argued the majority had made a "terrible error" by extending citizenship to children of foreign temporary visitors and people in the country illegally.

Following the ruling, Trump urged lawmakers on social media to begin work on legislation "TODAY," claiming no constitutional amendment was necessary to achieve the change through statute. Justice Brett Kavanaugh, in a concurring opinion, indicated Congress may have authority to establish exceptions to birthright citizenship for children born to parents present in the country unlawfully, which could provide a legal foundation for a legislative approach. Sen. Lindsey Graham of South Carolina and Rep. Brian Babin of Texas had already introduced legislation in the previous Congress that sought to narrow the definition of persons considered "subject to the jurisdiction" of the United States under the 14th Amendment.

The scope of so-called birth tourism — the practice of traveling to the United States specifically to give birth and obtain citizenship for a child — is a point of dispute. Estimates from researchers have ranged from approximately 2,000 to 39,000 such births annually, and a group of 140 university professors told the Supreme Court that the practice accounts for an "infinitesimal proportion" of U.S. births. Democrats have characterized birth tourism as a marginal issue, while Republican leaders including Sen. Ted Cruz have called it a blatant abuse of immigration law.

Amending the Constitution to restrict birthright citizenship would require approval from two-thirds of both chambers of Congress and ratification by three-fourths of state legislatures, a threshold considered extremely difficult to reach. The push for a legislative fix, by contrast, would face its own constitutional challenges given the Supreme Court's reaffirmation of the 14th Amendment's citizenship clause, setting up a prolonged legal and political battle heading into the 2026 midterm elections.