Thats a tautology. “What the constitution says” is the thing in question.
There's plenty in the US constitution which is vaguely worded, but you have to twist its words an awful lot to deny birthright citizenship.
Why not get rid of the whole charade and just replace it with "whoever is appointed to the Supreme Court can make up any law as they feel like it"? It has the same meaning, but it's an awful lot clearer!
In fact, I think there's a term for a ruler with complete power who's there for life, something like an "absolute monarchy"?
"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."
It's the second part that is in dispute and is not clear from the constitution's text what exactly it means and who it excludes. And yes, it has always excluded some people born within the borders, it is not a meaningless statement.
> A well regulated Militia
POV: you're about to hear the dumbest takes on the internet.
/s
Seriously though, were the founding fathers just master ragebaiters or what? More ink has been spilled over these two lines than any other in modern history.