The word jurisdiction is where it gets confusing. The meaning of that word does not map 1:1 to its modern usage.
To wit, if we read it as "subject to the laws of the land", then the invading army exception does not make sense, invading soldiers are subject to the laws of the United States and have been tried and convinced of violating them. Note, diplomat exception still makes sense, they _are not_ subject to the laws of the land.
So, how do you define jurisdiction in this amendment in a way that covers both invading soldiers and diplomats? I don't think it is super straightforward.
To put good faith on the table, I ultimately agree with your opinion here that birthright citizenship is settled and the vast majority of folks arguing against it are doing so in bad faith. But I also recognize the text of the amendment has holes to my eyes and could be updated for clarity.
It doesn’t cover diplomats either because courts do have jurisdiction over diplomats for certain non-criminal matter.
> vast majority of folks arguing against it are doing so in bad faith
What’s “bad faith” about it?
> To wit, if we read it as "subject to the laws of the land", then the invading army exception does not make sense, invading soldiers are subject to the laws of the United States and have been tried and convinced of violating them. Note, diplomat exception still makes sense, they _are not_ subject to the laws of the land.
I don't agree with your assertion here. Do you have more details on the claim that "invading soldiers [...] have been tried and convinced of violating them [US Laws]"?
As I understand it, invading soldiers are not subject to the laws of the United States nor are they protected by the bill of rights - instead they are enemy combatants and subject to military force. You don't arrest and charge active combatants, you fight them. If they surrender they become prisoners of war and would be covered under the treaties that apply to POWs, not civilian laws. They don't become citizens by surrendering.
I suspect the gray area would be around terrorists and stateless combatants, but the general principle that "people who are operating under the orders of a foreign government are not subject to the laws of the united states, but rather bound by the treaties between the US and their foreign state" would still apply.