I don't think it was that hard to see that there might be some bias in the polling data itself. Trump seemed very much like a candidate which would get a nontri

I don't think it was that hard to see that there might be some bias in the polling data itself. Trump seemed very much like a candidate which would get a nontrivial number of votes from people who would not "admit" that in a poll. I'd say he's exactly the kind of candidate that has people that will very loudly say they voted for him or keep completely quiet about it and less of a middle ground. Granted hindsight etc. I'd say the same will be true for some of the middle-right wing parties in Europe. Notably I think AfD in Germany will (unfortunately) get more votes than polls will indicate in the upcoming election(s). Le Pen in France could be a similar case but I'm not well informed enough on French politics to feel sure about that statement.