Lot’s of evidence to point to the meaning of natural born citizen to require 2 citizen parents, but it has not been definitively decided in a court of law.
Congress could define it with a constitutional amendment, but never has. They did try to define it by statute, but the Supreme Court had some cases that rendered the 1790 statue moot, and it is inactive.
greeneyes is absolutely correct.
The reason defining natural born citizenship was never a problem before the now is because of something called "derivative citizenship." Before the mid 1920s all women held the citizenship of either their father if single or their husband if they were married. This means that if a Irish man married an American woman, the woman would also become Irish. However, if an American man married an Irish woman, then the Irish woman became an American citizen. Consequently, if a couple was married with an American Father it was pretty much impossible to have anything but a Natural born citizen. (In the case of illegitimate children, the children received the father's citizenship unless the father was unknown in which case they inherited the mothers citizenship.) This system was rejected by the progressives as too "patriarchal", but that is the reality of it. Most of the Western world used to pass citizenship through the father.
Only now that the government allows a husband and wife to hold different citizenships independent of each other do we have confusion.
Natural-born citizens, are those born in the country, of parents who are citizens. That is the legal definition of the term, and is the definition that has been used by the Supreme Court in many cases. The issue is not only if Obama was born in Hawaii, but that his father was NOT a US citizen. Obama admits on his own fight the smears website, “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.”
If Obama was a “Natural born citizen”, he would NOT be subject to the laws of a foreign nation. He was a British subject the moment he was born, and he is NOT eligible for the Office of President.