Sometime during 1968-69 a Phoenix surgeon flew his wife to Mazatlan, Mexico so that she could deliver their son in Mexico. Dr. Flynn had lived for some time in Mexico as a youth, spoke fluent Spannish and had no qualms about having his wife delivered in Mexico. Still, I asked why he would do this when we had perfectly good obstetricians in Phoenix.
It was simple. Mexico, in order to prevent foreign nationals from owning Mexico, enacted laws that required 51% of the ownership of any Mexican property to be owned by a native. Dr. Flynn was ensuring that his son would be a Mexican citizen able to have full ownership in Mexico despite the fact that he would live in the U.S.
President Trump is right. People game the system in order to gain the rights of citizenship. Of course, the 14th Amendment states that a natural born citizen must be bound by the laws of the country and the state in which he or she resides, and I imagine that the same holds true in Mexico.
I have a hypothetical question. If Maria Consuelo Gomez-Ortiz, a member of the caravan coming north from a Central American country, say Honduras or Guatemala lies down on the U.S. Mexican border, one leg in Sonora and the other in Arizona, and has her baby is it a Mexican citizen, a U.S. citizen, neither or both?
Also, if a baby is born in the desert and there is no one there to document it does it exist?