In US v. Wong Kim Ark, the Court ruled that he had been born a US citizen despite both parents being non-citizens and only temporary US residents. Are you aware of that?
"Some authorities go further and include as citizens children born within the jurisdiction without reference to the citizenship of their parents.”
Once again, the court explicitly does not exclude children of non-citizen parents.
The sentence you picked had no bearing on the ruling, the previous sentence was what they held, as reaffirmed in WKA:
.United States v. Wong Kim Ark, 169 U.S. 649 (1898) In this case, Wong Kim Ark, the son of 2 resident Chinese aliens, claimed U.S. Citizenship and was vindicated by the court on the basis of the 14th Amendment. In this case the Justice Gray gave the opinion of the court. On p. 168-9 of the record, He cites approvingly the decision in Minor vs. Happersett: At common law, with the nomenclature of which the framers of the Constitution were familiar, it was never doubted that all children, born in a country of parents who were its citizens, became themselves, upon their birth, citizens also. These were natives, or natural-born citizens, as distinguished from aliens or foreigners.