I'd also say, with respect to polls, that 2020 is really different. For 1, you don't have 2 unlikable, dishonest, corrupt scumbags running. Biden is far more likable than HRC ever was.
Also, at this stage in 2016, Clinton and Trump were much closer than Biden and Trump are. PLUS, there haven't been any October Surprises like Comey's letter. I don't think the Hunter Biden stories have moved the needle much, if any.
538 has done some interesting analysis around 2016 polling.
On average since 1972, polls in the final 21 days of presidential elections have missed the actual margins in those races by 4.6 percentage points, almost exactly matching the 4.8-point error we saw in 2016.
https://fivethirtyeight.com/features/th ... all-right/