I do not see "natural" in there. Does not need to die at all. Obama could hand off to Biden with a crayon and used napkin then go on vacation.AMENDMENT XXV
Passed by Congress July 6, 1965. Ratified February 10, 1967.
Note: Article II, section 1, of the Constitution was affected by the 25th amendment.
Section 1.
In case of the removal of the President from office or of his death or resignation, the Vice President shall become President.