Doesn’t matter. When Barry Goldwater and John Tower voted against the Civil Rights Act of 1964, the black community turned solidly Democrat (98 percent +) at that point, and there has been little reversal. It may be that the late John V. Lindsay got 20 or 30 percent of blacks in 1965, however.
I would say the change came later when Lyndon Johnson started buying votes with his wealth redistribution “great society” plan.
The plan that destroyed black and white poor families in America. Giving them incentives to not work. Incentives to make dad move out for more benefits. Bumping the check by having another baby.
We’ll make you slaves of the state and give you just enough money not to starve and you vote for us. OK?