Reporting without bias on presidential candidates

At a recent convention in Chicago, a news correspondent asked her fellow colleagues if they could cover Barack Obama fairly. That correspondent, Mara Schiavocampo, is also a black woman. The colleagues she asked the question of are black as well.

To ask a white reporter if they felt he could cover John McCain fairly seems odd. What if you are a white Democratic woman and the question was asked of you? Most likely you are not a McCain supporter, but reporters are supposed to be unbiased and state the facts.

In her article, it appears to me that she asked four correspondents who are cleary Obama supporters the question, but did she ask any who were not? Do black Republicans not exist?
Or what about the white reporters who are equally as proud of Obama and what he has accomplished? Don't they face the same situation of trying to report on the candidate in an unbiased way?