Before the advent of Barak Obama, the accepted wisdom was that natural born meant born within the borders of the United States of a citizen father(before about 1970) or more recently, of a citizen parent. Because of tacit recognition that Hussein did not fit the category The Congress passed a resolution that McCain was natural born, primarily to clear Hussein, to get the whole question off the table. Where a candidate was born is probably no longer an issue that could actually hinder a candidate. Citizenship at birth or even current with a campaign is probably fading as a hindrance to being President as the Constitution is less and less relevant.
I’m as much an originalist in constitutional matters as anyone, but the “natural born citizen” requirement has really lost a lot of its relevance in an age when international travel and intermarriage between citizens and non-citizens has become so common.