Donald Trump is a media creation.
First, they created him by focusing on all that is bad and alarming. Outrage is good for ratings and they've kept anyone who will pay attention outraged since the emergence of 24-7 news. When you are outraged, the only thing you can agree on is that the status quo has to go and that even an outrageous candidate is better than none at all.
Second, they've enabled him by taking him seriously. Trump hasn't a clue about anything and yet they report on his candidacy as if it were a serious thing worthy not just of consideration but incessant focus. They've learned that the only thing better for ratings than alarm is Trump and so have focused on him as a ratings bonanza.
Our understanding of our world outside of our immediate experience is mediated by the media. There is no good reason that a reality-show star should become president except that he's already shown his ability to get ratings. Shows that get good ratings get renewed and shows with bad ratings are cancelled. The rest of the Republican field was cancelled and Donald has each month been renewed because he is best for ratings. Given the media's focus, the American people have decided that he must be the real deal.
It has become increasingly clear that Trump is going to become president and there is absolutely no good reason for this except for what he does for ratings.