It addresses the question of forms of citizenship.
We are all aware of “naturalized citizen”, which is a person who has fulfilled the legal requirements to be granted citizenship by the government.
There is also “jus soli” or “of the soil”, which is the citizenship form addressed by the 14th amendment. Jus soli is specifically limited to those “subject to the jurisdiction thereof”, which effectively mitigates against foreign dignitaries whose offspring are born here … yet it also stands against “anchor babies” in that their parent(s) have not subjected themselves to the jurisdiction of US law.
Then there is “jus sanguinis” or “of the blood” whereby citizenship is conferred on a child by the citizenship of at least one parent. US law requires that parent to be at least 18 & have spent 3 of the previous 5 years in the US (if I recall correctly from an issue re: the daughter of a missionary couple who married a foreign national where they were serving whose child was then denied entry to the US because he was not a US citizen).
Finally, there is “natural born citizen” which is generally understood as one born to two citizens of the US within the borders of the US. The difficulty with this “general understanding” is that the only place outside Article II it is addressed is Minor v. Happersett. There are indicators in Dred Scott, but I do not know how much of Scott has been overturned so it is currently moot.
Because it is a general understanding & not a defined terminology, there are significant differences of opinion re: “within the borders” - does that include foreign territories under US jurisdiction? military reservations? occupied lands? The one requirement about “natural born” which is not questioned is that both parents must have some form of US citizenship prior to the birth of the child.
None of this takes into account the derivatives associated with dual citizenship.
It will take someone with more information than I to state definitively the Mormon colonies in Mexico were US colonies, particularly as they were established in part to avoid subjecting themselves to the laws of the US.
It matters where Gov. Romney’s father & grandfather were born because Mexico is a “jus soli” state. IF the Mormon colony was not under US jurisdiction & IF the grandfather did not take steps to secure his “jus sanguinis” before his son, Romney’s father, was born then his father may have been a Mexican citizen. If this is true, then if he did not secure “naturalized” citizenship before Gov. Romney’s birth, he could not have passed US citizenship to his son, thereby causing Gov. Romney to be a US citizen “jus sanguinis” through his mother & “jus soli” due to place … but not “natural born” … the requirement of the Constitution. btw, Chester Arthur WAS ineligible as President, knew it … & took great pains to hide that fact. In this day of internet & 24/7 investigation, I would hope he couldn’t have gotten away with it.
Maybe all he needed was the “right” ideology.