Dicta is quoted all the time as if it were part of the holding. Other times it's aknowledged, if only obliquely, as dicta, but used for "guidance" anyway.
But yes, I read the Indiana case, promptly dismissed it, and forgot most of it.
And for Wong, all that stuff in the case is how they are analyzing the case and determining it. It would have been nice if Wong had wrapped it all up in one sentence, but they didn’t
But Justice Gray did manage a single paragraph:
The evident intention, and the necessary effect, of the submission of this case to the decision of the court upon the facts agreed by the parties were to present for determination the single question stated at the beginning of this opinion, namely, whether a child born in the United States, of parent of Chinese descent, who, at the time of his birth, are subjects of the Emperor of China, but have a permanent domicil and residence in the United States, and are there carrying on business, and are not employed in any diplomatic or official capacity under the Emperor of China, becomes at the time of his birth a citizen of the United States. For the reasons above stated, this court is of opinion that the question must be answered in the affirmative.
Those reasons were stated in a few paragraphs right above that final one:
The fact, therefore, that acts of Congress or treaties have not permitted Chinese persons born out of this country to become citizens by naturalization, cannot exclude Chinese persons born in this country from the operation of the broad and clear words of the Constitution, "All persons born in the United States, and subject to the jurisdiction thereof, are citizens of the United States."
VII. Upon the facts agreed in this case, the American citizenship which Wong Kim Ark acquired by birth within the United States has not been lost or taken away by anything happening since his birth. No doubt he might himself, after coming of age, renounce this citizenship and become a citizen of the country of his parents, or of any other country; for, by our law, as solemnly declared by Congress, "the right of expatriation is a natural and inherent right of all people," and
any declaration, instruction, opinion, order or direction of any officer of the United States which denies, restricts, impairs or questions the right of expatriation, is declared inconsistent with the fundamental principles of the Republic.
Rev.Stat. § 1999, reenacting act of July 7, 1868, c. 249, § 1; 15 Stat. 223, 224. Whether any act of himself or of his parents during his minority could have the same effect is at least doubtful. But it would be out of place to pursue that inquiry, inasmuch as it is expressly agreed that his residence has always been in the United States, and not elsewhere; that each of his temporary visits to China, the one for some months when he was about seventeen years old, and the other for something like a year about the time of his coming of age, was made with the intention of returning, and was followed by his actual return, to the United States, and
that said Wong Kim Ark has not, either by himself or his parents acting [p705] for him, ever renounced his allegiance to the United States, and that he has never done or committed any act or thing to exclude him therefrom.
(I've italicized what was indented in the original)
The court tries to give the reader the impression that Obama is a natural born citizen but it doesn't really say that he one.