IIRC, he had a hard time attracting blacks at the beginning of his campaign. IF he had quit a year ago, things may have been different for him. He probably thought at the time he had the lib white PHds, but needed poor blacks. He will probably lose some blacks now, but it won’t matter, since he won their votes in the primary already.
The difference between im and the Clintons is he does NOT understand America. The Clintons can at least pass for Americans. He acts like an alien who just knows the language, and nothing more.