It had plenty of weight behind it. The definition of NBC was given to satisfy what the term means within the Constutition in Art II Sec I, and it was given in rejecting Virginia Minor’s argument of being a citizen by virtue of the 14th amendment. It was then quoted and affirmed more than 20 years later in Wong Kim Ark, where Justice Gray noted that the Minor decision unanimously excluded children born in the country of citizens from the citizen clause of the 14th amendment. Virginia Minor was declared in Gray’s citation as a citizen by virtue of BOTH jus soli and jus sanguinis criteria. It was strong enough that Gray could NOT declare Wong Kim Ark to be a natural born citizen and instead had to find other means in which to say that Ark had become a citizen at birth. IOW, Ark was the type of citizen for which there was doubt. For NBCS, as Minor states, there was NEVER doubt.
It was merely dictum in Minor. The point in Minor was not to define the term natural born citizen for purposes of the natural born citizen requirement but rather to determine whether the 14th Amendment mandated that women have the right to vote as US citizens. Bingham drafted that Amendment about 80 years after the term was used for the presidency requirement which means it may or may not actually view the term “natural born citizen” similarly as the founders. Further, the term “natural born citizen” nowhere appears in the 14th Amendment. The Amendment merely states “[a]ll persons born or naturalized in the United States”; that is it protects the rights of citizens. The natural born issue was not important to the holding in Minor and thus merely dicta with no real weight beyond possibly being persuasive.
It was also merely dictum in Wong Kim Ark.