Nobody has ever claimed that a poor person has all the opportunity a rich person has -- nor would this even be desirable. What we have claimed is that, in America, riches and poverty are the most mobile and the least attached to non-economic factors. A classless society is not one where everybody has equal money; it is one where money moves toward productivity, instead of "class". The very people who argue that America is a country of millionaires who have no class are, unnoticed by them, making our argument for us.
When money is abundant and moves up and down ladders of class THAT, sir, is economic justice.