Actually, I think they CAN prove who they voted for. If the DEM voted in the primary on 6/3 - its safe to assume he/she voted DEM. However, on 6/24 - if that same person voted - it stands to reason that it was a vote for a REPUBLICAN - because of the runoff - and its also safe to assume if that person is black they sure didn’t vote for McDaniel. Is this a racist comment? No - just factual.
That’s not proof. It’s assumption.