> For instance if black men who support Republicans very grudgingly (enough not to vote say) are swept up in a broader wash of getting all black men to vote more, you’d see that pattern

Why? There is no reason for this assertion. There are equally likely begrudging black democrats, and higher turnout doesn't necessarily lean towards a side. You'd expect higher numbers in equal proportions on both sides, all else being equal.

> Another reading of the data is that these were votes against Biden/Harris or protest votes against the Democratic party for their lack of more aggressive action on racial justice

Yes. Away from Biden is functionally equivalent to towards Trump if that's how the votes were placed. That's saying what I'm saying, in part