“natural born citizens”....... The quote tries to confer citizenship only via the father and discards the citizenship of the mother.
“When Barack Obama Jr. was born on Aug. 4,1961, in Honolulu, Kenya was a British colony, still part of the United Kingdom’s dwindling empire. As a Kenyan native, Barack Obama Sr. was a British subject whose citizenship status was governed by The British Nationality Act of 1948. That same act governed the status of Obama Sr.‘s children.
Regarding BHO's mother...there are many unanswered questions and who knows where they might lead.