it was a different time when endemic racism was more prevalent across both Parties, where de jure segregation prevailed in the south and de facto segregation was present most everywhere else.
IF the Blacks wanted to hold Dems responsible for the syphillis experimentation over all else, then you'd never see such 90% + Dem majorities among black voters in most elections at all levels.
Guess they're smart enough to notice who sponsored, passed and enforced voting rights and civil rights legislation over the past 60 years and which Party is more inclusive in legislatures at all levels.
Also, which Party is trying to make it harder for them to vote.