The last election showed us, again, that Republicans will vote for conservatives of any color. What it most certainly did NOT show us is that blacks will vote for black Republicans.
Cain would be demolished in the black community no different than Ken Blackwell, Michael Steele, Lynn Swann, Allan Keyes, etc. Blacks are voting for government handouts and benefits first and foremost, race is very secondary.
Blackwell, Steele, Swann, etc were all bad candidates. Give blacks a good black candidate to vote for and the results would be different.