At the moment, I gotta say, I'm dubious about trusting Nate. Here's why: his calculations right now are way, way off those of his election prediction peers.
Nate Silver, fivethirtyeight.com, presidential prediction, polls-only forecast:
The Upshot Presidential Prediction, NY Times:
Princeton Election Consortium (Sam Wang):
Electoral-Vote.com (computer scientist Andrew Tanenbaum and his colleague-in-statistics Christopher Bates):
These analysts/sites all do election analysis based on polling. The methodology is obviously different to get such wildly different results. I will have to read the fine print, but Nate Silver is very much the outlier here.
Oh, wait: here's the fivethirtyeight.com polls-plus forecast.
Okay, that's the model that includes historical data and the state of the economy.