Obama would have thrown Dr. King under the bus if he got in the way of his ascending to the throne.
Which might actually be a reasonable or applicable comment, if A) There were the slightest chance that Dr. King would have spoken out against Obama, or B) Dr. King were still alive.
What sort of interaction do you think McCain would have had with Martin Luther King, Jr.? ... I mean, other than voting against Martin Luther King Day, voting against affirmative action, and even voting against measures to stop discriminatory hiring practices.