What so many people never seem to realize about politics is that nobody ever wins, the objective is to lose less than everybody else. The strategy of politics is to ensure that no-one is violently unhappy with government policy. The art of politics is to successfully re-define “happiness” every electoral cycle.
The basic point (with which I wholeheartedly agree) is that "incrementalism" isn't a failure to achieve one's objective, it's how one achieves said objective. The idea isn't to vote ourselves out of this this time, it's to keep voting ourselves just that little bit closer to what we regard as the most desirable political state of being. That's what "sustainability" really is; the process of sustaining something in a viable state or condition.