Not is she doesn't get 80% of the black vote. The dislike for the Clintons has become personal with blacks. If she's the nominee, Dems will have a hard time getting 50% of the black vote.
If the Republicans offer more of the same, these voters could vote for Hillary anyway, out of habit. No, the Republican candidate would have to offer a reason for blacks to vote for him, not just not vote for Hillary.
If she’s the nominee, Dems will have a hard time getting 50% of the black vote? Wrong, TN2K. Hillary as Dem nominee might well reduce black turnout, but blacks just won’t vote for Republicans. Hillary’d still get four fifths of the black votes, but the total number of black votes would be greatly reduced. As so many octegenarians and their descendants still worship FDR for “saving the family farm”, blacks likewise still vote for LBJ and his Civil Rights and Voting Rights Acts, even though Democrat LBJ needed Republican votes in the Senate to get the acts past Democrat filibusters.