As a blatantly slick marketing technique, I think it works well. But it rubs me wrong because there always has been class (in other words, two Americas) in the U.S. and--barring violent revolution--there always will be. The wealthy will always get more (in education, housing, healthcare, and so on) than the less wealthy. Edwards does not say he would change our two Americas into one America. He merely puts it out there as a diagnosis. And to that I say yeah, so?
The truth is Edwards knows well that he cannot solve the problem of "two Americas" and is only using it as a marketing slogan.
He might be able to alleviate some of the suffering associated with class/capitalism, but he is not going to do away with the divisions.
In contrast, there is Dean who is a no-bullshit kind of guy. When there's a problem he cannot solve, he says so up front. For example, when he admitted that single-payer healthcare is not doable in the near term.
Disclaimer: I was a Clark supporter who liked Dean, too.