“By the night before Election Day we should know who is going to win.”
I don’t think so. I don’t think many of the polls are accurate for several different reasons. Lland-line polling is essentially dead, and the pollsters have yet to find an accurate alternative; there have many articles written pollsters to that effect have been posted at FR. And i think there’s a ton of people that simply aren’t saying who they’ll vote for, particularly Trump people.
You could be right about the difficulties in polling particularly when we have a race like this one that features (love ‘em or hate ‘em) two very polarizing figures.
That said, there is no reason why polls like the USC Poll can’t turn out to be fairly accurate. These polls measure changes in the voting intentions of a fixed and large population of voters over time. That is very different than your classic telephone survey that, as you pointed out, is inherently a flawed methodology.
Will it happen that the USC Poll calls it right? Time will tell. If we really are looking at a big movement to Trump from the sick and corrupt Hillary over the next 70 days it will be visible in that poll.
Fingers crossed.