2. This article shall be inoperative unless it shall have been ratified as an amendment to the Constitution by the legislatures of three-fourths of the several States within seven years from the date of its submission to the States by the Congress."
This amendment defines how long a presidential term can be. Each term is four years and no president can exceed two terms.
Each president is only allowed to stay in office for a maximum of two terms. This encourages turnover so the nation does not stay under only one type of leadership and has the potential to expand from various perspectives.
In this interview with MSNBC, former President Bill Clinton asserted that presidents should be allowed to serve a third or even fourth term in office but only after they took time off following their second term. He attributes this change to longer life expectancies and that some politicians have incredible leadership that the country can continue benefitting from.