Personally, I've lost all faith in change (that matters) through the democratic process. As far as I can tell, the only way anything is going to change is through instability of either the economic or the ecological system. Sanders definitely looks good, though, as far as these things go. I just wonder if the US citizenry haven't been burned too badly by Obama to vote for another democrat promising a better way.
Sanders' plan is more long-term than to just get elected president and try to change everything. He wants to create a massive socialist movement of some sort, to try and fix the problems before they get bad enough that we need a real revolution. With any luck, his movement will last much longer than he lives. Keep in mind that's just based off my analasys as a leftie. But what I hear when he says "political revolution" is "I will not live to see these problems fixed, but I'm gonna get the ball rolling."