Indians born within the territorial limits of the United States, members of and owing immediate allegiance to one of the Indiana tribes (an alien though dependent power), although in a geographical sense born in the United States, are no more "born in the United States and subject to the jurisdiction thereof," within the meaning of the first section of the Fourteenth Amendment, than the children of subjects of any foreign governmentborn within the domain of that government, or the children born within the United States of ambassadors or other public ministers of foreign nations.
The last couple of clauses in the court's opinion make the argument that those born to foreign citizens are not US citizens even if they are born in the territorial United States. It doesn't just apply to the citizens of Indian Tribes. This opinion says that birthright citizenship based on ius soli.
Look at those words:
children of subjects of any foreign government born within the domain of that government
Highlighted part in particular. Born in a public hospital isn't within the domain of a foreign government.
the children born within the United States of ambassadors or other public ministers of foreign nations
If your parent is not an ambassador or other official representative of a foreign Government, then this clause does not apply.
So, under the 14th Amendment, how would a person born in a public hospital NOT be covered? How would they qualify for either of these only two exclusions to citizenship?