I'm not sure about the first "gaffe" where he said he's running for Senate, but the most recent one has been taken out of context. Kind of a stupid point to bring up if it's not true. It doesn't help more people vote for Trump if his supporters are lying and/or misinformed. Trump himself said it, as well which is also stupid because it's not true. Doesn't help his case.
I think Biden's a racist dumbass, through and through. But that's no reason to repeat whatever you heard without checking.