Then why weren’t American Indians born outside of their reservations on US soil not granted citizenship until 1924? (Through legislature, not judicial means)
They were subject to all laws in the US (when outside their reservation), unlike those with diplomatic immunity. Could it be that “subject to the jurisdiction” actually meant sole jurisdiction?
Sure, you could make that argument. As I said, I think there is enough wiggle room that it should have been left up to Congress, which would mirror your point about the Indians.
But you can't credibly argue that the Supreme Court simply ignored the "and subject to the jurisdiction thereof" clause as that other poster claimed. The Court very clearly pointed out the diplomatic immunity exception still applies.
The Amendment was poorly drafted, and the decision could have credibly gone either way. It didn't go the way I wanted, but unlike some other wacky decisions, there was at least a reasonable argument to be made for the way it went.