So then based on what you say, B.O. is a natural born citizen.
As everyone recalls due to the Oriental Exclusion Acts Japanese could immigrate into the US but could never own land (in California and other states where the law restricted land ownership) or become citizens.
Their children born here were, however, citizens.
After WWII the law was changed regarding Japanese immigration and all the Oriental Exclusion Acts were repealed.
Little old ladies who'd been in the US since they were teenagers were then allowed by the revisions of the Walter-McCarren Act to apply for citizenship and did so.
The new laws didn't just apply to Japanese who'd not yet immigrated ~ they applied to everyone.