Prior to the 14th automatic citizenship was restricted to those Natural born( both parents U.S. citizens Wilken vs Elk) . The 14 amendment( did not affect Natural born) gave native born citizenship to those born with partial allegiance,such as one parent a U.S. citizen or born of parents ( Wong Kim Ark case) who were legal immigrants. U.S. supreme court defined Natural Born as Children who parents were U.S. citizens(Minor vs Happensett). Natural born citizenship as defined a number of times by Congress as CHILDREN OF CITIZENS SHALL BE CONSIDERED NATURAL BORN.
If someone want to change the meaning of Natural born and Article two of the U.S. Constitution, it would require a Constitutional amendment,until then it requires both parents to be U.S. citizens to be Natural Born.