I heard an American political commentator comment today about the supposed stability the US two party system provides. But I found myself disagreeing with him. I think it can be argued that the two party system is what's causing some of the current problems in the US. Specifically I think that if there were more than two viable parties in the US some of the polarisation would disappear, because there would be more outlets for people's political preferences. The Republican Party for example might not have as many of the hard right religious types that turn off many voters. Those folks would likely have their own party, and the Republicans would be more centrist. Of course the fact that the President is elected in the US means the effect of more parties would be somewhat different than in parliamentary systems like that of Canada.