"When there is no middle class left, only peasants and rich liberals, then the revolution can happen."
When there are only peasants and rich liberals, then their revolution will have been achieved. At that point, they may have another revolt, but not along Marxist lines...
And there you reveal the true goal of today's radical- not to establish a Communist utopia but to seize power for greed and then commit genocidal pay-back, largely against those perceived to be white and Christian, but also whomever they view as oppressive. Republicans and business people of all backgrounds.