So, without doubt this "I had to remind him he was black" bit is racist (and probably not the persuasive argument she thinks it is). Everyone seems to realize that, to judge from the reception it's getting online.
How to account for her closing argument, that she 'might be willing to seal the deal in more ways than one' if he changes his vote, though? No commentary I've seen addresses what is really a vicious argument in several ways:
1) It assumes his moral judgment about how to vote is for sale, and not even for cash, but for a mere night's pleasure;
2) It proposes that her sexuality is for sale, and not even for cash, but for one vote out of tens of millions in a state that is all but certain not to be swung by his vote nor even his influence;
3) It suggests that his morality is therefore cheaply bought;
4) ...and that her sexuality likewise.
It is not extraordinary that someone might make a proposal like this, but it is extraordinary that they would do so in public -- without shame -- and be called on it by no one whatsoever as far as I can tell. This seems to be quite in alignment with our self-declared elite's mores on sexuality.
How do we deal with this?