The 11% Hispanic turnout and the 12% Black turnout numbers were not too helpful, either.

Hillary promised more of the same and they didn't show up to get it.  

I believe that the Hispanics had been promised immigration reform every four years by Obama and they didn't accept his excuses as to why  (justified though it was!) he couldn't deliver on those promises.  

Other than that she wasn't Obama, I haven't found anyone who has explained why Hillary couldn't get the blacks to the polls.