Beg to differ.
In the simplistic form, if that were so, the children born to diplomats in the US would be citizens - and they are not.
There are better, more detailed arguments, but the interpretation of the 14th Amendment is about as twisted as the interpretation of 2nd Amendment in the the Miller case.
“In the simplistic form, if that were so, the children born to diplomats in the US would be citizens - and they are not.”
They are not because of the “subject to the jurisdiction thereof” clause, which does not apply to the children of illegals.