1) The black president didn't say anything like that, so your first point is a moot one.

2) True...it is hard.  The problem is that the current president thinks he is the greatest at everything, and, when confronted with a little criticism, he feels the need to attack his predecessors (falsely, I might add).  I personally don't think he meant anything negative by his "he knew what he was getting into" (or something similar) comment, but when he feels the need to throw a tantrum when a little criticism is thrown his way, I lose all desire to defend him in this instance.

Past presidents....even Nixon...were smart enough to know what they didn't know (and Nixon was probably one of the best in knowing this).  The current occupant not only thinks he knows everything, but thinks that he is the world's foremost expert as well.