When it comes to predicting elections, Moody's Analytics comes about as close to the seers of the crystal ball as we can get. Accurately predicting every election since 1980, with a perfect scorecard in 2012 (including all electoral votes), the Moody's model is pretty hard to beat.
The Moody's model relies heavily on economic data, including real income, real housing, and gasoline prices, as well as political data on a state-by-state basis.