This leads to the second factor: Harris will prove to be the most disastrous vice presidential nominee since Sen. Tom Eagleton, D-Mo., had to resign from the McGovern ticket when it turned out he had been subjected to shock therapy treatments for mental issues (I am not criticizing mental illness or its treatment, but in 1972, Americans simply did not want to think of a potential president having mental illness).
As a presidential candidate, Harris had wavered between embracing the most radical positions and then opportunistically changing to more moderate positions when she got blowback. She was as unreliable in her policy positions as she was in her attacks on Biden. She aggressively attacked Biden on four different occasions and has since repudiated her own words. If Biden is exhausted and hiding in a basement, his running mate is energetically bouncing all over the place with no consistency or reliability.
During the primary, Harris was at 15% support in July 2019. She then dropped as low as 3.5% support by November 2019, according to Real Clear Politics. Even in her home state of California, she had dropped to fourth behind Biden, Warren and Sanders – and was only attracting 8% support from her own constituents before she dropped out. In fact, 61% of Californians thought she ought to drop out of the presidential race, according to a poll by the Berkeley Institute of Governmental Studies for the Los Angeles Times.
The Democrats (and propaganda media) believe that she will be powerful in attracting the African American vote. This is undermined by the objective reality that in November 2019, after months of campaigning, a Quinnipiac University poll showed Harris was fourth in attracting Black voters.