A revolution is coming — a revolution which will be peaceful if we are wise enough; compassionate if we care enough; successful if we are fortunate enough — But a revolution which is coming whether we will it or not. We can affect its character; we cannot alter its inevitability. - Robert Kennedy
Nach dem Aufstand des 17. Juni
Ließ der Sekretär des Schriftstellerverbands
In der Stalinallee Flugblätter verteilen
Auf denen zu lesen war, daß das Volk
Das Vertrauen der Regierung verscherzt habe
Und es nur durch verdoppelte Arbeit
zurückerobern könne. Wäre es da
Nicht doch einfacher, die Regierung
Löste das Volk auf und
Wählte ein anderes?
After the uprising of the 17th of June
The Secretary of the Writers' Union
Had leaflets distributed in the Stalinallee
Stating that the people
Had forfeited the confidence of the government
And could win it back only
By redoubled efforts. Would it not be easier
In that case for the government
To dissolve the people
And elect another?
-Berthold Brecht, "Die Lösung"
Karl Marx saw a revolution of the working class as inevitable because he believed that the wealthy classes would never allow any improvement in the conditions of the workers at the cost of their own profits. This revolution did not happen in much of the developed world. The ballot box opened an alternative path for workers to get proper treatment through government regulations and social programs. 19th century parties calling for revolution and meaning it became 20th century parties mentioning it symbolically.
I prefer to take a systems theory approach: when a system is stuck in a dysfunctional equilibrium and people cannot knock it into a better equilibrium by normal processes, then revolution becomes an alternative some may start to consider.
When a system is in equilibrium, it doesn't like to move out of it; it tends to bring things back to the equilibrium state. If the state is stable enough, it will strongly resist movement away. But if the system is dysfunctional, there will be many in the system who will want/need/demand change. As the system resists change, the stress on the system will increase without release. Earthquake analogy. When the stress gets released, and a change sufficient to overcome the equilibrium takes place, we might call it a revolution, if the system is of sufficient scope.
I'll tip my hat to the new constitution
Take a bow for the new revolution
Smile and grin at the change all around
Pick up my guitar and play
Just like yesterday
Then I'll get on my knees and pray
We don't get fooled again
-The Who, "Won't Get Fooled Again"
Unless the revolution is sufficient to actually destroy a system (very few are), a new equilibrium will arise. The various conditions which shaped the previous equilibrium will still be in existence (restrictions on resources, human nature, and the like). As a result, the new equilibrium is likely to be dysfunctional itself. The specific rules, roles, and leaders will have changed, but the overall appearance is the same. The USSR, the one place instance of a revolution from within a country which is related at all to Marx's predictions, ended up quite similar to czarist Russia even though many details were different. This situation is a change of details without changing the overall appearance. A lower level of dysfunction in a system is less likely to produce a superficially similar system after a revolution, but they are much less likely to have a revolution in the first place.
So what about the quote from Robert Kennedy? He posits a choice between two sorts of revolutions. One is the sort described above: a release of tectonic stresses in a nation-system. The other is a revolution by transcendence: a change in the conditions which shape the current equilibrium, thereby making the current situation a disequilibrium one which will itself resolve into a new equilibrium. The second kind is the only sort of revolution which is of any use, ultimately.