Obviously, Blacks voted for Obama for a number of reasons: race is one of them; many Whites voted for Hillary, and later McCain, for the same reason. I don't believe, however, that Obama giving them, exclusively, a voice was one of the reasons Blacks voted for Obama, and I don't think that's what he wants to do. Most Black people believe he will be a good president for all Americans, something which they obviously have a real stake in.
They voted for him because he was both Black, relatively young, and held many of their beliefs, which speaks to what Tuner said, about Blacks usually going democrat. Had a Black conservative been running for the democratic nomination, against Hillary, I believe most Black people would not have voted for him or her, because his or her ideas would have been contrary to most of theirs. The same would go for a general election between Hillary and, let's say, Alan Keyes.
Either way, Black people can't, through the power of their votes alone, elect anyone to the presidency, which is what you seem to imply. Hispanics, in the southwestern states, who usually vote Republican, switched sides, despite many pundits stating that this group would never vote for a Black candidate for president. The same thing happened in a number of former "red" states, with the hick vote; and, in Florida, it also happened with the typically right-leaning Cuban vote. Obama actually has a huge mandate, because of the mosaic of people who voted for him, which is why many Republicans, in Congess, will likely have to support many of his policies.
Obama beat Hillary because of sustantive reasons: he has a powerful intelllect, was able to stay humble, undivisive, when confronted with the most controversial issues, and was able to overcome the race issues that many Whites hold with people of other races, because most people saw something special in him, something more than just color. His words urged them to go beyond superficial details, regardless of what one thinks about the man.
In addition, I find it ridiculous that you'e trying to turn racism, and its fruits, onto the group that has faced the most racism in recent history: Blacks (from all over the world). And, this is coming from a White person, someone who comes from the group that, for hundreds of years, has, as a people, dominated the rest of the world. Your argument is flawed, in a number of ways. All of the United States of America voted for Obama, on a landslide level. Live with it.