Depends on whether the real goal is "kill those people" or "make a better life for the rest of us". The first is easy; the second is harder.

I assume it often starts with "kill those people" and once that nasty business is out of the way and new people are selected to replace them there's a very strongly implied "Now you people make a better life for the rest of us, or else we will start over."

I think you're confusing successful revolutions with revolutions. Way more likely the revolutionaries succeed in doing a bit of damage and get crushed.