RACE IS NOT ABOUT DNA. I think that's where people get it wrong. A biracial person can identify as whatever they want because they are not only black. However, the truth of the matter is that once white people see any trace of those full lips, kinky hair, darkened skin, and round nose, they will automatically classify you as black and treat you as such. From the words of Chimamanda Ngozi Adichie in her book Americanah, "Race is not biology; race is sociology. Race is not genotype; race is phenotype."
In other words, race is not your genetic makeup or the bubble that you circle next to the words "African-American" on any public application. The intrinsic characteristics of being black is why racism exists. To the biracial person who would rather not identify with his/her black side to escape the discrimination associated with it, that notion is a myth and is not possible for every biracial person (For those who can pass for white, congratulations! You're lucky!).
One cannot destigmatize black skin. One can't say, when he/she is being discriminated against, "Oh, I'm half-white". That doesn't matter as long as you are visibly black. To white people (and other races), a biracial person's other race totally disappears when those black features are present. Imagine President Obama saying that he would not want to be known as the first African-American President because his mother is white. Sounds ludicrous, right? So, biracial people do not have to classify themselves as black; that is not a problem. The problem is when one uses that other race as a get-out-of-jail-free card. That card doesn't operate in this game.