I was making some very large generalizations in my original comment for the sake of brevity and argument. Thank you for taking the time to pick them apart;)
> If you keep the structure of the US government but change the electoral system for the Congress to one which produces more proportional responses, you don't have the same degree of incentive for disproportionate concessions to a minor party to form an administration.
My original point was that the Tea Party has essentially shown that a more proportional system of government isn't any more functional or effective than a two party system. The Tea Party has essentially captured the Republican Party, not too dissimilar to how a minority party would make out-sized concessions of a coalition government in a parliamentary system. Both cases result in gridlock (or something that closely resembles it).
> If you keep the structure of the US government but change the electoral system for the Congress to one which produces more proportional responses, you don't have the same degree of incentive for disproportionate concessions to a minor party to form an administration.
My original point was that the Tea Party has essentially shown that a more proportional system of government isn't any more functional or effective than a two party system. The Tea Party has essentially captured the Republican Party, not too dissimilar to how a minority party would make out-sized concessions of a coalition government in a parliamentary system. Both cases result in gridlock (or something that closely resembles it).