Maybe I am not as surprised as everyone else because I think they both have a range and they will move around inside their ranges - up to the top and down to the bottom; but so long as they don't escape their ranges, which look extremely stable, Clinton wins.
When she was winning by 10% I said the same thing. So this isn't me being under-alarmed unless you also say I am under-exuberant.
If anything, I suspect that, given he has hit a top of 42.5% or so three times in a row, he is no longer a 44%-max trendline guy. Enough people cannot abide him that he can no longer reach the 44% which is the bottom of her range. So he is doomed.
Also, the debates don't have teleprompters. Trump ad-libbing has a 38-39% appeal. Again, he is doomed.
Trump has no surrogates. She has brilliant ones. So he will be outspeeched by a multiple of 5 or 6.
Also he loses around 2-3% on election day because he has no ground game.
So she wins by around 7-8% on election day. That will be enough to give her the win in the needed swing states.