Look, XIV (and XXII, for that matter) are horribly drafted and say things in plain English that contradict the intentions of the drafters.
But “some dead guy meant to say THIS” is not going to prevail, certainly not in a case like an EO over birthright citizenship. A President has the authority to order Secretary Pompeo not to issue passports to the US-born children of illegal aliens, he does not have the authority to define “subject to the jurisdiction of” in a way that binds future litigants or US district courts.
“he does not have the authority to define subject to the jurisdiction of in a way that binds future litigants or US district courts.”
Sure he does. He’s the one that enforces the law. Don’t be silly.