Clearly Obama is biracial like almost every black in this country. That he is called black is imprecise but reflects both a cultural and legal tradition in this country where the presence of any black blood was normally sufficient to classify the person as black. In fact, at the time of Obama's birth, the union of his parents violated the laws of several states which persisted in banning "interracial" marriage until it was finally outlawed by the Supreme Court.
Obama's race has been used both for and against Obama since his candidacy was first announced by partisans on both sides. The fact that it seems to have been considered less important to voters than to the pundits and the media is testimony to how far we have progressed as a country since I was young and living in a legally segregated part of the country. Whether one supports or opposes Obama, I would hope that almost all of us would consider that to be a noteworthy milestone.
With respect to media coverage, I believe the track record is mixed. On Fox News and conservative radio talk shows, Obama can do nothing right. He is deemed responsible if a child catches a cold and anything good that does happen is deemed to have happened despite his interference. On MSNBC, the reverse is true and I am reminded repeadedly of the cartoon of Obama walking Bo:
The rest of the media reflects its traditional biases -- both conservative and liberal -- but seems less extreme. That Obama's press is still relatively positive is consistent with the treatment afforded most presidents early in their terms (even GWB, who was given almost a complete pass early on and then again after 9/11).
With respect to the question of racism, I believe that almost everyone in America is conscious of race and that it affects our thinking and actions more than most of us would care to admit. Calling people racist in the discussions on this forum is like most other forms of name-calling -- it's more a way of evading a discussion of issues on their merits than it is an argument in its own right. As a personal attack, calling an individual racist violates the terms under which we agree to frame our discussions in the interests of civility on this forum. It is completely inappropriate.