The polls were off by about 2%. Unfortunately, it made a lot of a difference because of the winner-take-all system. These polls, and aggregation models are also not produced by the media themselves, they just report on it as they do for the weather forecast.

Also we didn't "all know it". How would that even work? "I can feel there is a great enthusiasm for Trump, and he will win the election, although he'll get 2 million fewer votes than Clinton"?