With regards to your first link, we had multiple universities claim that they had correctly predicted every presidential election since 19XX predict Bernie would be the President. These are not scientific or rigorous. All serious polling aggregates have her at a 75+% chance of winning on the low end with most being above 90%. Her pathway to 270 lies in States that all have her with a 5+% polling advantage.
With regards to your second link, the US is entirely different than the UK demographically. We are much more diverse and the minorities in the US are overwhelmingly supporting Clinton. Also with regards to Brexit, referendums are notoriously hard to poll because it is hard to predict turnout for one off events. There is alot more science and history involved with US presidential elections.
With regard to you third link, it is a daily tracking poll. These are generally less rigorous than a poll that has a larger sample and is in the field for a few days. Most polling aggregates have the race somewhat closer than last week, but not anywhere near 1 point.
Of course anything could happen and we will keep campaigning through election day, but the bottom line is that this has been a remarkably stable race from the beginning and one in which Hillary has been the overwhelming favorite.