that the electoral power of white Americans may well persist for a long time to come

Its not the electoral power of White Americans, or at least just the electoral power of White Americans.

The issue is that there are a lot of people that specifically see the way that race, gender, and so on, are being used in a dishonest way to, basically, score points. That while it is absolutely a true and fair criticism to say that feminism - speaking to intersectionality for a moment - had issues with only catering to white issues in the past. And, to their credit, that makes a lot of sense when the sort of people who have the time and money to concern themselves with issues related to feminism, rather than working two jobs just to eat, are going to inherently end up being issues that middle and upper-class people deal with. Lower class people simply do not have the time or resources to go to marches, in comparison, and so the movement was reasonably focused on a set of issues that did a poor job of addressing lower-class, and specifically black issues given that most middle-class and upper-class people are and were white.

However, to have that same criticism now used to attack people for their race and gender, to throw insults of bigotry, is something that many people identify as toxic, or just something they don't agree with.