Hands up if you know who is the dumbest president to ever hold office in America. George W. Bush has won this notorious title from some people over the years. Sure, not all the ill-will is earned, yet he was known as the world’s worst public speaker who leaned towards inventing words and saying things that were quite often meaningless and baseless. Still he is no match for the average joe as he can boast of having the second-lowest IQ from the list, with 138.5.