It strikes me that the reason we didn’t see it coming is because of the echo chamber effect.
Secondly — one of the reason polls have been unable to predict it is because one side was so heavily demonized, meaning a percentage felt they were unable to speak up out side of the voting booth.
There is a real issue with the far left stifling discussion — And I say this as someone who considers themselves extremely liberal. In fact, I’m extremely liberal and British, which is already more left than the US!
We recently voted to left the European Union (not Europe as people always make the mistake of saying). When I say that I voted leave, people are stunned knowing how liberal I am. However that is because the media reduced the argument to stay=inclusive=good and leave=racist=bad.
I wanted to leave because the EU is a corrupt and undemocratic mess. Being told that I’m old, stupid and right wing is not even reductionist — it is wrong (at least on the point of stupid and right wing).
Perhaps if there was a proper conversation about what Trump voters needed out of their president, what they aren’t happy about, how they envision America moving forward, rather than being told they were horrible backwards people lacking humanity thing would be different.