I have written extensively on this subject. The rule is that if one parent is a US citizen, the child is considered a US citizen, no matter where they are born.
As to birth citizenship for the children of foreigners, the court has not ruled specifically on anything except that the children of permanent legal residents who are born here are citizens. A permanent legal resident is almost a citizen, and is a foreign national who can actually v**e here.
If "all persons born or naturalized in the US and subject to the jurisdiction thereof" were citizens, then Elk would have won his case, and there would have been no need for the Indian Citizenship Act of 1925, granting full citizenship to Indians who were born here of parents who were born here.
I******s cannot v**e (mostly) cannot serve in the US military with few exceptions, cannot receive citizen benefits, and cannot be tried for treason. The fact that they must obey the laws is not "subject to the complete jurisdiction."

The origins of this language are a bit hazy, but it must be recalled that the purpose of the 14th Amendment was to correct the infamous Dred Scott v. Sandford decision (1857) and recognize citizenship for the newly-freed s***es (but not members of Indian tribes living on reservations). The language of the Citizenship Clause derived from the Civil Rights Act of 1866, enacted by the same legislators (the 39th Congress) who framed the 14th Amendment. The Civil Rights Act of 1866 conferred citizenship on “All persons born in the United States, and not subject to any foreign power, excluding Indians not taxed.” (Emphasis added.) Foreign nationals resident in the United States, and children who become citizens of a foreign country at birth (by virtue of their parents’ citizenship) would obviously be excluded from this definition.

Granted, the language of the Citizenship Clause deviates slightly from that of the Civil Rights Act of 1866, but there is no compelling evidence that the 39th Congress intended a different meaning. In fact, the sponsor of the Citizenship Clause, Senator Jacob Howard (R-MI), stated that its language “is simply declaratory of what I regard as the law of the land already,” explaining that “This will not, of course, include persons born in the United States who are foreigners, aliens, or who belong to the families of ambassadors or foreign ministers.”

The record of the debate in 1866 is illuminating. When Senator Lyman Trumbull (D-IL), Chairman of the Judiciary Committee (and a key figure in the drafting and adoption of the 14th Amendment) was asked what the phrase “and subject to the jurisdiction thereof” meant, he responded: “That means ‘subject to the complete jurisdiction thereof.’ What do we mean by ‘complete jurisdiction thereof’? Not owing allegiance to anyone else. That is what it means.”

There you have it. The actual words of the men who wrote the Amendment, and the meaning of the Amendment in 1868 when it was v**ed on and ratified. Attempts to justify "birth citizenship" simply because the mama gave birth on US soil is not grounds for citizenship as intended by the authors of the Amendment.

https://lawliberty.org/what-did-the-14th-amendment-congress-think-about-birthright-citizenship/

https://constitutioncenter.org/the-constitution/historic-document-library/detail/civil-rights-act-of-1866-april-9-1866-an-act-to-protect-all-persons-in-the-united-states-in-their-civil-rights-an