[JohnG45]

... why preface citizen with natural born if it didn't have a different definition.

Bingo!

So simple, so obvious.

[phockthis]

And considering that the founding fathers chose their words VERY carefully, I’d have to believe that they meant 2 US citizen parents and born on US soil...

[Conscience of a Conservative]

So simple, so obvious.

Yes, it is obvious that "natural born citizen" is narrower than "citizen." "Natural born citizen" excludes "naturalized citizens," who are born as foreigners. The framers wanted to prevent the possibility of a foreigner emigrating to the U.S., becoming a citizen, and becoming President.