This is a spin-off from another thread, which I have not contributed to. The topic of discussion there has been steered away from what I would like to discuss, so I am creating a new thread instead of hijacking that one.
In that thread, Aldebaran expresses concern about the American two-party election system, which seems to exclude any third parties that want to contribute to politics, especially to the election of the president.
How exactly would you model a government that specifically prevents this from happening? If you wish to point to other governmental models, such as what we see in English parliament, explain how the system differs legally from that of the US, and how these differences lead to multi-party contribution in politics.
In America, the two major political parties tend to adopt and incorporate the agendas of several groups that would potentially have been parties in other political systems. For example, the Democratic party may be made of those who, in other systems, would have been Socialists or Labor (although I do not want to argue whether Democrats are socialists who endorse labor, I was just using an example). I think this system works well, because it prevents small groups with radical agendas from gaining disproportionate recognition in government, such as what we have seen before with victories in England for parties such as the BNP with blatant and outspoken racist agendas. While these small minority groups may hold majorities in small areas in America, they almost never have great influence in state or national politics.
Another argument supporting the two party system in America is that the system is not legislated at all; it developed naturally within the very relaxed boundaries of the US Constitution. The Constitution itself does not show a preference for limiting the system to two parties, and yet the two party system has developed regardless. In some cases, when differences between agendas forced a split or created a situation in which three or more parties must exist to incorporate all of the popular agendas, there were indeed more than two political parties in America.
The best benefit to America’s political system that I see are that the two political parties are, by necessity, moderate. No republican could be elected on a platform of religious authoritarianism, and no democrat could be elected on a platform of complete communism, because they alienate too many voters. (Whether or not the candidate ignores the platform on which they were elected is a different story, again not what I intend to debate here). I believe that most dopers would also agree that moderate politics are almost always superior to radical or excessive agenda politics.
How would you design a government which prevents excessive agendas supported only by minority groups from gaining disproportional political power, while at the same time giving each of those often excessive and radical groups a voice?