You can support an end to the 2-party oligopoly and vote for the lesser evil. Doing both does greater good.

I don't support revolution, because it's not the best viable way to improve things, let alone very viable at this point. A much better way is for the good people to ostracize (as much as possible) the bad people. Imagine if Bush's daughters had disavowed love for him, over his needless violence. It may well have had an effect, and if not then at least been a consequence to him, serving as a warning to others.