Usually the polls are a good indicator of what's going to happen. And usually Nate Silver has been an excellent interpreter of what the polls are saying.
But for this election I think turnout is going to be the key -- and the polls aren't able (at least not yet) to factor the comparative merits of the GOP and Democratic Get Out The Vote efforts into their numbers.
I can't, either -- but I can make a guess. And my guess is the Democrat's GOTV in many states is going to far outdo the GOP's.
Let's set aside that the GOP has promised me, repeatedly, that if I don't contribute they'll lose. That may be simply rhetoric.
But the GOP has also told me repeatedly that if I give them $24 they can get one voter to the polls. The Democrats have told me that if I give them $3 they can reach 100 voters. So that would be 800 voters reached for the same $24 amount.
Now those figures aren't directly comparable; one is for voters contacted in an effort to motivate to vote and the other is for voters actually motivated to vote. But unless the Democrats have a .125% success rate with their outreach, the Democrats look to be a lot better at this kind of thing. That matches what I think I've seen in the last few elections, starting in 2008.
I think the Democrats have been doing a better job of reaching out to their voters and urging them to vote in this election than the Republicans have, and that that's going to make a key difference of several percentage points in several close races. My prediction: Democrats at least 48+3, Republicans no more than 49.