I just don’t think that’s a very big demo. Anybody who’s suddenly motivated to keep the White House white and estrogen-free is more than likely a foaming-at-the-mouth MAGAt, who was already motivated to put their guy back in office. There will of course be a few people who fit that description, and probably many more diet racists and sexists who will just stay home if their options are Trump or a “left-coast liberal woman,” but I don’t think they make up a significant-enough proportion of the voting public to outweigh that latter group you mention, who couldn’t muster much enthusiasm for Biden but are amped-up to vote for somebody younger, healthier, and more dynamic.

Obama won by healthy margins in '08 and '12, and Hillary – the least likeable candidate that’s made it to the top of the Democratic ticket since Dukakis – still won the popular vote. I think the people who would vote against a black woman for President were never going to vote for a Democrat in the first place, and given the general aura of relief and enthusiasm I’ve seen in left wing spaces since the announcement I think Harris is going to be riding a wave of support from the left, even if half of it is just from people who are glad they don’t have to hold their noses to support a doddering octogenarian because the alternative is fascism.