As for the black vote, I don't see a Hillary coup driving it away.
The Dems have ruined black families, patronized blacks with skin-beats-ability dogma, despoiled black neighborhoods with initiative-sapping handouts and wrecked black kids with unchallenging, feel-good curricula.
Yet blacks keep voting Dem in overwhelming numbers.
Short of poisoning Harlem's water supply, blacks will always turn out to pull the lever for whatever amoral machine hack the Dems choose to run.
The blind dedication of blacks to the Democrat plantation is actually a fairly recent phenomena in historical terms. From the Civil War until the mid 20th century, nearly all blacks were Republicans. It was only after WWII that blacks stopped seeing the Republican party as the party of Lincoln and the Democrat party as the party of the KKK.
It would take a lot to reverse that, but taking away the nomination from Obama at this point would probably be enough.
The black electorate are the ultimate sheeple. If the Dems stayed in power and wanted to reintroduce slavery, they would still vote 85% to 90% for them.