The legal battle over President Trump's executive order restricting birthright citizenship is largely over five words in the 14th Amendment: "subject to the jurisdiction thereof." The court's interpretation of this phrase could have significant implications for who qualifies for U.S. citizenship. The administration argues that the phrase applies to those born legally and not temporarily in the U.N. The ACLU, which is defending the plaintiff in the case, argues that it applies to most born people on U.US soil, excluding narrow exceptions like the children of foreign diplomats. If the court sides with the president, children of H-1B visa holders and parents with temporary protected status could lose automatic citizenship.