She's right. American never was great. Not in the way that people who support Donald Trump think it was. What they liked about America was to other Americans oppression, enslavement, death, genocide, ethnic cleansing.
What Trump really means is that he wants to make America white again. As it was before we had our first African-American president. It's a racist dog whistle. I should have seen it coming, we all should. For all the joy and relief in getting over the race barrier in 2008, for other Americans that was defeat. Seeing a President as someone who had power over you, and for that person to be black must have been too much of a stretch for some.
But the truth is the President doesn't actually have power over you. The President has symbolic power. We've seen how little actual power comes with the Presidency, after seeing the effect of Republican obstruction for the last six years.
Our challenge is to learn how to live with each other. Blacks, imho, have been amazingly peaceful given all the provocation. That's smart, of course. But amazing nonetheless. And white racists -- we have to make sure you don't get to run our country. Because then it wouldn't be America any more. The good things about America would be gone.