The most salient demographic change from 2008 to 2012 was the drop in white voters.
The following table summarizes these estimates for all racial groups, and compares the results to actual turnout.
Another anomaly for 2016 is the polling statistics. They were for the most part well off base.
NY Times: If current polling holds for 2016,
(Blue is Democrat.) Even day of election polling was way off: “If today’s general election polling holds true, Hillary Clinton will easily defeat Donald Trump.”
What happened in the actual 2016 vote? White voters came out in strength and there was a mild decrease in black voter turnout.
Michigan and New Hampshire voted Democrat.