The use I am referring to-
Urban Dictionary: Uncle TomUncle Tom
Uncle Tom is a term used by black people to try to convince other black people that working, education, living well, and setting a good example for their children is selling out.
Apply that to the more PC definition you'll find in the more "mainstream" Dictionaries-
Uncle Tom - Definition from the Merriam-Webster Online Dictionary1 : a black who is overeager to win the approval of whites (as by obsequious behavior or uncritical acceptance of white values and goals)
2 : a member of a low-status group who is overly subservient to or cooperative with authority <the worst floor managers and supervisors by far are women…Some of them are regular Uncle Toms — Jane Fonda>
Use a dash of common sense and life experience in the USA and Obama is the commonly held view of what an Uncle Tom is.
"I believe in a Spinoza's God who reveals himself in the harmony of all that exists, but not in a God who concerns himself with the fate and actions of human beings."
--Albert Einstein, 1929