It’s because of history. White people would never have accepted a mixed person calling themselves white and having the same privileges as a white person. They were still slaves and property. I don’t think that even today that the typical white person would accept a Barack Obama or Colin Kaepernick calling themselves white, despite coming out of a white woman’s body. Black people, for the most part accept them as black. These are the rules that white people made up. I’m just used to it. Growing up if you were even slightly mixed, you were black. I’m starting to see some people use the term bi-racial more, but trust me if you get arrested by the police they will put black on your arrest report, as the self-styled “caublanasian” Tiger Woods found out. So, while it may be an archaic system, it’s not the time to conveniently bring that up to call the protest of this black man, Colin Kaepernick, into question.