Sam Wang at Princeton does a regular analysis of how he expects the election to go based on state polling where it is available, His latest iteration is here
As he puts it in his brief analysis
As longtime readers know, I use all available state polls to calculate an estimate of where the Presidential race stands on any given day. The methods are detailedhere. Basically, I use the median and estimated uncertainty of each state’s recent polls to calculate a win probability. Then I calculate a compound probability distribution of all possible combinations (2.3 quadrillion of them)
On the off chance that sparsely-polled states start to look competitive, or if evidence emerges that the electoral map is actually scrambled, I am considering using the Google Correlate method to fill in missing data. Google Correlate was remarkably useful tool in the primaries, and is an attractive alternative to using 2012 election results.
He does not feel this election will be “that different” from what we have seen before.
Oh and by the way? His method was apparently very accurate in predicting that Trump would be the Republican nominee.
Make of this what you will.