The legal battle over President Trump's executive order restricting birthright citizenship largely boils down to five words found in the 14th Amendment: "subject to the jurisdiction thereof."The big picture: The court's interpretation of that phrase could have massive implications for who gets to be an American — and therefore enjoy the rights and responsibilities that come with U.S. citizenship.Context: The 14th Amendment states, in part, that "[a]ll persons born or naturalized in the United St...