Nate Silver’s 538 site.
Sort of bogus, since he seems to “forget” a lot of the state-level polling that is more favourable to Trump by heavily weighing MSM polling while de-emphasising professional houses. He has Ohio as leaning Hillary, yet professional house polling in Ohio has been leaning Trump +2-5% for over a month. Same with places like Iowa, Nevada, Colorado, etc.
The trouble with Nate Silver’s “chance of winning” is that it tracks polls exponentially not linearly. The polls it’s based on can change by a few percent but the “chance of winning” changes exponentially and by 10x the poll change.
That is the way his “chance of winning” chart is set up. People need to remember that.
So it looks way worse than it actually is, plus it’s based on polls that are proven to be severely D and W oversampled.