first thing i agree with you on, there is a major danger that if the dem's just throw up another career trash politician or something too radical hoping to get some as yet unknown demographic. there is the distinct threat that A. trump might win again and B. you get some one just as retarded that starts a cycle of picking a new president just to get rid of the old one, not on making any real progress as a country.
a bit like that period in roman history where the Praetorian Guard worked out they actually had the power being the swords around the emperor so they kept ousting emperors and installing puppets every few months to few years, at one point they even auctioned off the position of emperor to the highest bidder. you could get a similar situation only the people become the Praetorian's in that scenario.