Marxism holds that the middle class will eventually disappear, as the world is polarized between a few large business owners and the masses of the proletariat. Small and independent businesses would disappear, and most of the middle class would be pedestrianized. The middle class was always a sticking point for Marx, and there is some question whether this is really prediction or wishful thinking. I say wishful thinking, because Marx knew that he could not achieve his socialist end-state with a middle class in place -- he had to drive the middle class into the proletariat.
In a large sense, that is what was are seeing at the Democratic Convention -- the effort to convince the middle class that, against all reason and reality, they are actually not well-off, that they are marginalized victims. It is an attempt to pedestrianize the middle class. Thus we get this classic quote from Rahm Emanuel, via Matt Welch:
The truth is, the Bush crowd has been giving the middle
class a thumping. This November, the middle class is going to give it
right back. This election comes down to a simple question: do we want
four more years of Bush-McCain or do we want the change we need?
is only one candidate from the middle class, that understands the
middle class, and that can deliver the change the middle class needs:
Barack Obama. A strong economy depends on a strong middle class. But
George Bush has put the middle class in a hole and John McCain has a
plan to keep digging that hole with George Bush's shovel.