What if one of the parents is a citizen and the other is not but the child is born in the U.S., is the child then an American Citizen or not?
If one parent is a citizen, the other is not, whether the child is born in the USA or not, the child CAN be a citizen.
I speak from experience.
Both my children were born in hospitals in the Philippines. I had to submit, "Reports of Birth Abroad" to get them recognized as citizens of the USA.
Had they been born in the USA, or on US soil (The Naval base hospital would have done the paperwork) they would have automatically been US citizens.
Maybe the child should decide at the age of maturity?
I'd say, IF the non-citizen is a LEGAL immigrant, then, yes the kid is a citizen in that case.
For that matter, if two legal, immigrant non-citizens have a child, but both have been legal in the US for say a decade or more, I'd be OK with automatic citizenship for the child.