The average person is simply unable to evaluate competence, especially from news clips and "debates". The median voter is not a highly competitive white collar knowledge worker with a background in STEM necessary to evaluate complex topics with objectivity. Instead its the fry cook, the retail worker, the warehouse stocker, blue collar tradesman, liberal arts graduate, etc.
What really happened was that the pool of politically active citizens expanded, and now because of the shape of the normal distribution we are dealing with a sort of political endless summer - which media in particular are all too eager to take advantage of for political power.