With the weather man, I could keep track of when it rains and doesn't. If it rains significantly more or less than 80% of the time they say there's an 80% chance of rain, I can say that their model is bad.

I can't think of a similar way to evaluate Silver's election forecasting model. They very clearly aren't independent probabilities, and his model changes significantly from cycle to cycle. Was his model good in 2012 when every state went to where he predicted the likely probability was? Was it bad when his model said Hillary had a 71.4% chance of winning?