The Supreme Court's ruling striking down Trump's executive order on birthright citizenship hands open-border activists another victory while exposing the fraud of automatic citizenship for children of illegal aliens. This forces the administration to its Plan B of blocking pregnant foreign nationals at the border, a necessary defense against the deliberate exploitation that turns every birth into an anchor for chain migration and welfare claims. The decision matters because it sustains an incentive structure that undermines legal immigration and burdens American taxpayers with the costs of sovereignty surrendered at the delivery room. The Fourteenth Amendment's clause granting citizenship to those "subject to the jurisdiction thereof" was never meant to extend to the offspring of foreign nationals who owe no allegiance to the United States. Original understanding and the amendment's history affirm that Congress and the executive retain authority to define entry and citizenship against such maneuvers. Allowing birth tourism to dictate policy mocks the constitutional order that places immigration control firmly with the federal government. Trump's resolve to close this loophole restores the basic right of a nation to decide who joins its citizenry.