90% of blacks also voted for Clinton and Gore. It has more to do with the majority of blacks being Democrat than Obama being black. A few Republicans who were black ran for office this election and they lost as well with garnering very little of the black vote.
It was actually closer to 80%, but I agree that many just vote along party lines, which marginalizes them. Heard a black talk radio guy discussing this and he said the reason black issues aren't addressed is because dems know they have the vote NO MATTER WHAT so they don't bother.....and repubs know they don't, so they don't bother.
Like he said, black have been voting straight dem for 40-50 yrs, and what has it got them? Poverty, horrible neighborhoods, bad education, etc...