It's pretty amusing that the candidates in this upcoming election have him dropping by as a "campaign boost". I'm sure most of them view this just as the Republicans viewed the Dubya effort towards the end of his two terms.
Regardless of what the apologists say, the dramatic decline in approval is startling against the backdrop of what many people viewed as one of the worst President's in history. He had approval ratings at the start based solely on the fact that Bush was gone and yet STILL he's gone into the tank at a meteoric clip.