Very interesting discussion! Time constraints prevent me from replying to many issues I'd like to address, so I'll just comment on a couple historical points Starhawk made:
Athens "Senate"
In the 5th Century BC it was the "Assembly", which consisted of all male Athenian citizens 18+, rich or poor. In practice, of course, it was rare for more than a few thousand to show up, but any adult male citizen could attend, speak, propose legislation, and vote. This "pure" democracy also had a representative element, i.e. the Council of 500 which set the agenda for Assembly meetings. Council members served for a year. Membership was divided equally among the city-state's districts, which presented candidates from whom council members were chosen by lot. The term limit and random selection tended to reduce political corruption and intrigue. Of course rich and capable men could become "more equal" than their fellow citizens through lavish spending, conspicuous civic virtue, fancy rhetoric, and spectacular accomplishments (e.g. Pericles), but the Athenian system probably gave the "common man" more political power than any other in history.
References:
http://mars.acnet.wnec.edu/~grempel/...democracy.html
http://www.historyguide.org/ancient/lecture6b.html
Roman Senate
Contrary to popular belief (including mine), the Roman Senate was primarly an advisory body, not a legislature. During the middle period of the Roman Republic (e.g. the Punic Wars), power resided in several popular assemblies: the "Comitia Curiata", "Comitia Centuriata", "Comitia Tributa", and the "Concilium Plebis". According to Wikipedia, these councils all had legislative, judicial, and electoral powers. Both patricians and plebeians made up these bodies, except the Concilium Plebis which allowed only plebeians. While it seems overly complicated, the Roman system of checks and balances prevented dictatorship and aristocratic rule for several centuries.
References:
http://en.wikipedia.org/wiki/Roman_assemblies
http://en.wikipedia.org/wiki/Roman_Senate
There was also this point from El_Phil:
"Finally history shows people want their opinion listened to..."
I think history shows that people want to be heard mostly when they have a grievance, e.g. when they're overtaxed, evicted, exploited, incarcerated, etc. While John Q Icaran may not have the right to parade down the street with a sign reading "THE PRAETOR SUCKS!", if he's reasonably well off and generally left alone, why would he want to?