According to the article I read about the film, he's Wallace's male nurse. It makes a lot of sense, when you see how uncomfortable this guy looks when Wallace refers to him as "best friend". The whole scene seems so awkward and tragically racist, it makes me feel kinda sorry for Wallace (but, looking at his "achievements", not so much), the sad bitter man he became.
But he did condemn his acts and segregation on the whole once he became a Christian and asked forgiveness. Not that that undoes the immense damage he caused and still causes through his political teachings.(Nixon, Reagan & HW Bush all follwed his principals in quiter ways with their presidential platforms.) But it is of interest.
It was obvious to me that his "best friend" was his nurse & uncomfortable with the statement. Of course he traveled the world with him! No one who isn't paid well is going to take care of wiping this man's bum!!!