Oh, I did say he was a candidate, not that I would want to bet an uncomfortable amount of money on either Harding or Trump, for the title of "least intelligent."
Trump may not be bright as most sane people use the term, but he has the ability to read a room just like a Vegas "psychic" or a con man. If one believes those who think that Trump is rich, but only a fraction as rich as he claims to be, he has been living off of reading rooms for decades. He created an image of "Donald Trump" that was a lot of other people's wish fulfillment, and rode it all the way to the White House.