Why? Because he's scared, and he's a racist asshole.
"Of course, former President Donald Trump’s campaigns are always nasty work; that’s to be expected from a loud-mouthed, racist, sexist, petty, congenital liar of a candidate. But Trump has always singled out Black women for his most denigrating abuse."
https://www.msnbc.com/opinion/msnbc-opinion/trump-kamala-harris-attacks-racism-sexism-rcna163313
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@XaoslordErie
Good. We'll see how the American public responds to this hate filled bastard 
has spent his whole life painting himself into this very dark corner, I don't see him getting out of it any time soon.