From Dr. John C. Eastman:
Here’s the crux of the dispute. The text of the Fourteenth Amendment’s Citizenship Clause provides that “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.” That text has two requirements:
1) Birth on U.S. soil; and 2) Being subject to the jurisdiction of the United States when born. In recent decades, the opinion has taken root, quite erroneously, that anyone born in the United States (except the children of ambassadors) is necessarily subject to its jurisdiction because everyone has to comply with our laws while physically present within our borders. Those who drafted and ratified the Fourteenth Amendment had a different understanding of jurisdiction. For them, a person could be subject to the jurisdiction of a sovereign nation in two very different ways: the one, partial and territorial; the other full and complete. Think of it this way. When a tourist from Great Britain visits the United States, he subjects himself to our “territorial jurisdiction.” He has to follow our laws while he is here, including our traffic laws that require him to drive on the right rather than the wrong (I mean left!) side of the road. He is no longer subject to those laws when he returns home, of course, and he was never subject to the broader jurisdiction that requires from him allegiance to the United States. He can’t be drafted into our army, for example, or prosecuted for treason for taking up arms against us.