The black vote shifted to LBJ and the Democrats simply because LBJ promised to pass another future civil rights law just as good as the Voting Rights Act ~
For black voters it's like Goldwater wasn't even running.
That is just wrong, it was a massive landslide, history making, Johnson even won the Protestant vote and it was the last time in history that the democrats won the white vote and he did it with 59%, LBJ won everybody, just about every category of voter that there was.