I believe concentration of power and the lack of transparency is what causes the problems in both systems. A "centralized" government that works for the people is possible, as long as we avoid those things. Make the democratic process as direct as possible, don't create any positions of great power. Have all decision-making be completely transparent, so the little power that people have, they are unable to abuse without getting caught. If no one has a lot of power (be it in the form of political power, or money), no one has the power to control people.