The following critical commentary is not directed at Ridenour who I very much admire, but to reveal the extent of racism in the USA. Even progressives like Ridenour are affected by the ubiquity (def.) of racism that is always a part of the arsenal of the capitalist ruling classes in the category of "divide and conquer" that is used to secure their self-serving rule from any threats emanating from the people.
In racism the surface characteristics of people become the primary mode of thinking about them. Because Obama has a Caucasian mother and a Black African father, he still has a number of surface Negroid characteristics of Black Africans, and the characterization of him as a black persists. This is because the capitalist ruling class instilled in their working class subjects that whites were superior of blacks to insure the toleration of their use of slaves that were necessary to develop the resources because of the shortage of labor in the early history of the USA.
Obama was largely raised initially by a white mother and more-so by a white grandmother who was a vice president of a bank in Hawaii. The latter two shaped his thinking about about social reality, and that mentality, particularly being raised in a upper-middle class home, was milder in form in multi-racial Hawaii (I lived there for five years) than on the mainland. His self-concept and ideological views were largely that of every upper-middle class white kid of the US. Yet, he is still identified by his surface characteristics as a Black African-American, even by progressives such as Ridenour.
The Democratic Party leaders and the ruling class used this racism to manipulate the American people into voting for him. He was packaged as a different kind of candidate that would bring a non-racial administration to America to provide a cover for their policies of increasing militarization of the police forces and more onerous restrictions of civil rights, increasing censorship, increasing surveillance of ordinary Americans, more aggressive foreign policies, etc. In short, he was the perfect candidate for his time and for our masters. Once again, the capitalist ruling class fooled ordinary Americans.