To me what this shows is that despite the Occupy movement and all the talk of the 99%, economic populism still has limited resonance with Americans. We just aren't very angry with the plutocrats. A majority of Americans still fears big government more than big business and the rich, and many on the left are more interested in ending foreign wars or protecting the environment than in union activism.
Why aren't we angry with the rich? Maybe because we really sort of are rich. I may be in the middle as contemporary Americans go, but compared to all the people who ever lived I am still in the richest 1%. That makes it hard to get really angry about economic unfairness.