Tabby you phrase things like an irrationalist but I think we probably agree on Affirmative Action.
Only I think it does apply to the Presidency. Lots of people voted for him with the color of his skin being a strong factor. That's how AA works. The skin color isn't everything, but it's a big factor. If you are smart and black you have a good chance of getting into great colleges. It takes a lot more than just being smart and white. The bar is lower for black people, but there is still a bar.
The bar for the presidency is very, very high. Not any black person could become president. But given one has all of Obama's tools AND they are black, they can be. And he was. A white person with similar tools probably never even becomes a US Senator. Doesn't become editor of the Harvard Law Review. Etc.