Trumpism Failing?

I was listening to an excerpt of a speech Trump gave the other day, which theme was that Kamala Harris is not too smart.  What stood out to me was that the audience was almost completely silent.

It was only recently that his support base would go bananas when their hero made derogatory comments about his opponents–especially black women. Is it possible that the bloom is off the rose here, i.e., that these morons have simply heard enough of this hateful garbage?