Fortunately Article I, section 9, paragraph 3 provides that.
"No bill of attainder or ex post facto law will be passed. "
The President has sworn to uphold the Constitution of the United States. He has an obligation to clear this matter up once and for all. No power of mobocracy and indeed the power of the press can change his position in this matter.
You know if the Clinton appointee decides against Obama, you can bet Bill spoke about an appointment after Hillary is elected.