Bill O'Reilly played a clip last night from 2011 of Obama ridiculing Trump for five minutes at a White House dinner...really nasty and unfunny (except to some of the Democrats in the room). Really showed Obama's true personality.
Obama hates Trump so much that I wouldn't put it past him to have him "liquidated" (as the Soviets used to term it) if it looks like he will beat Hillary.
That would certainly cause unpleasantness. If you get my drift.