I see no evidence of any bases, or bases being covered here.
The Republicans favor entrepreneurs, people who run their own businesses. The percentage of Blacks who fit this description is much smaller than it is among White people.
The Republicans are more often against funding public education at the college level than Democrats. Black people attend public colleges at a much higher rate than White people.
Republicans favor the suburbs over the inner cities. Black people are more often urban or rural dwellers, and tend to npot be suburbanites.
Republicans are against Equal Opportunity provisions and 'quotas'. Most Blacks favor these.
Blacks benefit more from public assistance programs than Whites. Republicans oppose public assistance programs.
Pretty much all the rabid racists left in the US favor Republicans. There was a reason why Reagan went to Phildelphia, MS to start his campaign. Nothing ever happened there except the famous multiracial lynching, and he didn't go there to denounce that.
There are plenty of reasons for a Black American to vote against some Democrats, but a whole lot more for him to vote against a Republican.
Ward Conally is famous for the same reasons that a talking dog is famous: for the fact that he is an oddity, not for the wisdom of his words.