Obviously, Harris faced more of an uphill battle as a Black woman.
The polling boost Harris received after Biden stepped aside had less to do with Biden -- although everyone was relieved after his debate performance and years of dogshit polls -- than with the idea there would be a major course change.
And there was, but it was in the wrong direction as far as the Obama and Biden 2020 coalition was concerned, and the Harris campaign did nothing but double down on it.