I am sorry that you just don't get it, but you would if you were black and they were questions your legitimacy. I bet you would then understand. I, again, am sorry this is lost on you or that you are just being obtuse for the sake of argument.
This is the weakest part of the "defend him at all costs" argument. His opponent went through the same demands, the only difference is he released his on Hannity's site early on and quashed the question while Obama did not. Saying it is okay to demand it of a white guy, but you should treat a differently pigmented person differently is definitely not "judge not by the color of the skin", it is quite the opposite of that.