I'm going to write this once, since I'm tired of explaining
k_187 writes | about 10 years ago
it in comments on every damn story that has anything (however tangentially) to American Politics and our system of election:
Well, first I'm going to link wiki:
Which amazingly enough has a rather good explanation of Duverger's Law and why the system in America has ended up like it has. Of course, to make it explicitly clear, I'm going into Intro to Political Science 101 Mode and explain it again.
In any system that uses a "first past the post" system of election, in other words, single member plurality districts. Where one winner is chosen by gaining a plurality of votes (i.e. more than the others) in any given district will inevitably coalesce into two major political parties. Lets look at an example.
Suppose, for the sake of argument that in some random district in a newly created representative democracy, there are three candidates from three also newly formed political parties running for office. Lets call these three parties, A, B, and C. NOw also suppose, for simplicity's sake, that the final vote ends up with party A getting 40% of the vote, party B getting 25% and party C getting 35%. in an SMPD, candidate A would then be elected. 4 years later, the next election rolls around. Because B and C's total votes would be larger than A's alone, logically it would make sense for the two of them to form a coalition to run against A. As only one candidate would be elected, they form a new party D which wins with 60% against A's 40%.
THe fluidity of the coalitions that exist in American Politics dictates that in any case where a plurality of votes selects the final candidate, those opposing that candidate will be able to organize against that candidate and then win. Labels are mostly irrelevant, as we can witness in the current make up of both the Democrat and Republican parties (although it is possible that in 10 years this point may be moot, as Congress has been becoming more extreme, in that there are fewer liberal republicans and conservative democrats in Congress than there were 10 or 15 years ago. Granted this means that new members are centering around the medians of the parties, not that Congress is becoming more extreme, simply that there are fewer in the middle ((i.e. the party platforms have changed little, there is simply more party cohesion)) what this means for party cohesion remains to be seen).
Finally, the only way to change the two-party system that exists in America is to change the method by which our politicians are elected. Given the functions of Parties in American politics, one cannot simply eliminate the two current major parties and expect to not end up with a similar situation at some point in the future. How exactly to change the election system I leave as an exercise to the reader.