Ta-Nehisi Coates has a piece at The Atlantic that got me thinking. For a white person to vote for Obama is racist. The one drop rule means that they are voting along racial lines. Normally I like Coates’ writing, and I agree with his general sentiment. However, it still seems like we are stuck in the same mode of racial thinking. Obama has one white parent and one black parent. Why is he still considered black? I know there is an element of self-identification involved, but as a society, we treat him as black because of the one-drop rule. Black…