Though I WILL say. I'm not surprised in either a Gay man being 2nd in American Idol or a Black Man being President.
We have gay senators, gay lawyers, gay judges... gay people everywhere. Outside of a few bigoted bosses who may fire gay people for being gay. Not to mention, singing is seen as well... a "gay" act.
Most homophobic people's reaction to a gay singer would likely be "Yeah no, duh." just like how they would re act to a gay ice singer.
When Ricky Martin came out as gay, it was largely treated as a "Yeah like we didn't already know that" moment. Being gay may have actually HELPED.
While, Obama... the number of people actually racist (and homophobic) are actually VERY low beyond minor biases that can be overcome fairly easily. Most peoples racism is restricted to being slightly more nervous when a black guy walks by the a white guy.
A Harvard educated, suit wearing everyman isn't exactly going to worry them. Additionally, give a racist person the ability to vote for a Black man of their party, or a white man of the opposite party. I'll bet they take the black man every time! They'll just bitch that because of such and such they needed a black candidate.