From reading Dreams From My Father by Barack Obama, it's clear that the absence of his father left a vacuum in his life with all the unresolved attachment/separation issues that that usually entails. Every one of us can identify with that - if it is not a father we have lost then we have experienced some sort of loss, perhaps a separation, a bereavement whether of culture, identity or family member. Of course, to lose something so central as a father figure at such a young age has a profound impact. Obama seems to feel that he derived some recompense and satisfaction from the rewarding mission of bonding together with others and helping them. Identifying with black culture appeared to help him 'fill in some of the gaps' in his identity and he seems grateful for that, wanting to give something back to the people whose color and heritage he shared.