One of many interesting ideas in the Ministry of Defence’s Strategic Trends study is that the middle class may become revolutionaries: taking on the role Marx expected of the proletariat. My instinctive reaction to this is that it is implausible, but, on reflection, it is more likely than it first appears.
The slogan “you have nothing to lose but your chains” clearly does not apply to people who do have something. Few things can create a social conformist as the combination of a good income and a mortgage. Both history and current circumstances suggest this does not always apply
Also consider the current situation. The proletariat has shrunk in developed countries, while the gap between the middle class and the rich has increased. This leaves the middle class in the same relative position as the proletariat used to occupy. We have exactly the same motives, tempered by greater absolute (as opposed to relative) prosperity.
We are clarly a long way from violent revolution in developed countries. However peaceful change can also be revolutionary. What would happen if a significant chunk of the middle class started voting for socialist parties, or even for green parties?