2016 Postmortem

You won't hear much discussion of it because no one really has any data with which to interpret it.

Hillary got some 6 million fewer voters than Obama in 2012.
Trump got some 2 million fewer.

That suggests that the GOP already lost all the fed up/disgusted/demoralized voters and Hillary had more of them to lose this time around.

Another way to look at it though is that this is effectively the second national "election" that Hillary lost. 1 primary and 1 GE. She's won one primary. She's 1 for 3. Trump was in his first national election. Her negatives could have been more "embedded" than his. His were fresh and more malleable. Hers had time to "harden". You build up a "I'll never vote for her again" kind of reputation running that much.

I suspect though that the real problem was that her campaign banked on her negatives being better than his and worked that angle almost to the distraction of anything else. That, and the presumption that her minority support would dominate. It didn't.