If I'm correct, not American here, every 4 years the people of the US elect a President and a Vice President. A President can run for re-election at the end of his first term, but not his second consecutive term.
While this system prevents dictatorships, it has one flaw, every 4/8 years a "complete noob" becomes President.
Why not a system where you guys elect several Vice Presidents (which may be from different political parties) every 4 years and from that pool of Vice Presidents (who have served at least 4 years as VP) you elect the President where the President will serve 4 years and will not be consecutively re-electable. This way all Presidents will have at least 4 years experience in the Executive branch.