President Obama may or may not be a racist as racism is a matter of the heart and there is but one judge of that. His behavior doesn't appear to make him one. However, one could reasonably conclude that he is less color-blind than Rush Limbaugh. It is very uncommon for Rush to comment on race one way or the other except in the context of an observer of how the race card is being played by those in power, either in politics directly or by the media. And there's no evidence in his persoanal associations or attitudes--at least over the last 30 years or so--that he sees the world through a racial prism or bears any personal racial prejudice; selected comments taken out of context, notwithstanding. In fact, rational people who actually listen to Rush regularly from whatever political pole, would be hard-pressed to argue otherwise.
Obama, however, sat for 20 years in Reverend Wright's militantly anti-white church. Wright is a deliberate racial radical and very divisive character. Obama recently jumped to an irrational, race-driven conclusion about a Boston cop investigating a possible break-in based, quite evidently, on nothing more than his own racial prejudices and opinions. There is doubtless more in his record as a politician and community organizer that would reveal racially driven policies, actions, and attitudes--however well-intentioned or even effective they might be. This doesn't necessarly make him racist, of course. But it does reveal a certain "beam in the eye" of some on the left (like Al Sharpton) who are quick to condemn a Rush Limbaugh on very flimsy grounds, while ignoring, if not upholding, the race-baiting or blatantly racist "sins" of those in their own camp.