Income disparity

This chart from the Congressional Budget Office shows  Average US Household Incomes from 1979 through 2007. I agree it is hard to believe, but the source of the information is accepted by politicians on the right and the left.  
I don't know what segment you fall in (and I am the last one [make that almost the last one] to complain), but even if you are one of the top earners in our country, it is hard to maintain that our problems are due to the middle class. Can anyone looking at this graph tell me what constitutes middle class nowadays?

Demonizing one another is not the way to go forward. We need to sit down, talk, listen and decide anew what the promise of our country is. Right now, the peaceful demonstrations by the citizens of Tunisia, Egypt, Libya and other middle eastern countries are showing us what courage really looks like.