[CodesInChaos]

> why most modern democracies have reduced themselves into two party theater

Is that true? It's certainly not the case in Germany, where we have ~6 relevant parties at the moment. I'm pretty sure other European nations, like Italy, often form their governments from multi party coalitions as well.

In the US I'd primarily blame the way votes are counted (majority of majorities). I'd expect other parties to rise to relevance if a different voting system was used, e.g. parties getting seats in the house of representatives proportional to their votes, instead of composing it from the winners of the individual districts (or a hybrid, like in Germany).