Of course, as an aside, the LA times polls which always had a Trump ahead were also significantly out - he lost the popular vote (or had last time I heard an hour ago). As did Bush and one of the Democrat presidents (can't remember which one). It's of no great significance given that the election is state based - and if it was a single national vote no doubt the numbers would be slightly different anyway, given that voter behaviour in the non-swing votes would alter. It is worth a passing mention though - Trump only got a minority of the voters.
The more interesting thing I haven't looked into today is voter registration in places like Florida. In Bush v Gore, Bush won not because of the hanging chads but because large numbers of black voters were excluded, by 'voter purging', disenfranchising felons etc. Not sure of how much of that is still in place in Florida or other states.