President Donald Trump's birthright citizenship argument before the Supreme Court faces an April 1 showdown in Trump v. Barbara — but a new legal analysis warns he's about to get demolished by history. The case challenges birthright citizenship under the 14th Amendment, but constitutional experts say the Framers of the amendment already settled this debate with unmistakable clarity, Slate's Dahlia Lithwick wrote Monday.According to constitutional historian Anna O. Law, author of the forthcoming "Migration and the Origins of American Citizenship," the amendment's language leaves zero room for interpretation, which states, "all persons born or naturalized in the United States and subject to the jurisdiction thereof, are citizens of the United States and of the state wherein they reside.""It’s very significant. They could have said that the rights of equal protection and due process are for all citizens. They chose not to use all citizens. It says 'all persons.' And I think they were very mindful of the fact that a bloody civil war had just concluded. They were mindful of the fact that states had been discriminating against Black people. And it’s the states who were going to do any sort of discrimination," said Law. By specifically writing “all persons,” she said the Framers were making it abundantly clear that U.S. citizenship stood above state citizenship and that the federal government would enforce the protections of state citizenship. When pressed on whether "all persons" included children of Chinese immigrants, whom Congress and public opinion actively despised at the time, they responded unambiguously."And there are extensive discussions about, Surely you don’t mean the birthright citizenship clause to mean the children born to Chinese immigrants? And the Framers said, No: Yeah, we mean them. Because even though their parents cannot gain citizenship because there are laws banning them from naturalization, we do mean the children," said Law.She called out that birthright citizenship is in the Constitution as an amendment that was ratified in the 1860s, not a law passed by Congress. "Why did they do that? The Framers did it the hard way. They went through the Article 5 process of changing the Constitution instead of just passing a law," she said. They feared a law could be wiped away by a future Congress or Supreme Court. Putting it in the Constitution made it "more durable," she said."They meant to raise the bar of what it would take to amend it and to get rid of it and to change it. And so birthright citizenship is not just a law passed by Congress. And you certainly cannot change it by executive order," she added.