Very true.
However, the overall 'racial tolerance climate' has changed in the past 15 years.
I've said this before, and more than once:
Obama's election demonstrated to me that the reality of racial equality in the US was far less than it appeared.
Racism was not accepted in 'polite society', but it simmered and bubbled below the surface.
Once Obama got elected, the racists all started coming out of their caves and out from under their rocks.
The "Birther" bullshit. The 'secret Muslim' garbage, which was especially ridiculous given how much negative publicity the pastor at the Obama's church generated.
https://en.wikipedia.org/wiki/Jeremiah_Wright_controversy
Once Trump gained some traction as a candidate, the hatred escalated.
Once Trump won, it got worse.
Can you imagine a "Nazi & KKK Rally" during ANY previous administration?
And can you imagine the sitting President saying, after the Nazis killed someone, that there were 'very fine people on both sides'?
With Trump's anger and hatred, people were emboldened to say stuff that would have been 'not okay' previously.
With it now more acceptable to say that sort of crap, the people who feel that way now realize that there are a lot more of them than anyone realized.
Which accelerates the acceptance.
Much of it is still 'unsaid', but the number of people that would never vote for a woman, or never vote for a person of color is not small.
As I said in the post you quoted (you left it out, but I understand and appreciate trimming the quote for brevity), if Harris is the candidate, I hope I'm wrong about it.
But I can't see her winning the election.