538 recently put out this article
Explaining how they screwed up predicting Donald Trump's rise.
While I tend to steer clear of US politics (the US has less of a political system and more of a personality system) I also made a terrible but similar mistake; but with Bernie Sanders.
While my error was not recorded on the blog, it was still something I said quite often, that Sanders has no hope in hell of winning.
While I encourage everyone to read the article linked above, I have taken one important note out of the victories of people like Rob Ford:
Voters these days are far more willing to accept an extremist candidate than they were just a decade or two ago.