And yet I get Republicans on this forum saying to me they don't need the black vote. Clearly you do, unless you just enjoy the challenge of trying to win without them.
The GOP can win while doing pathetically with black voters. However, if they can improve their performance with black voters, that makes it (for obvious reasons) significantly harder for the Democrats to beat them...I mean, even ignoring a dramatic change like that suggested in the OP, blacks moving just enough to the right could flip, say, GA, WI, PA (and that, in 2020, would've been enough to seal the deal for Donald).
