There should either be no limits to how many viable political parties there can be, or none at all

@ Mr. Murphy

It's a pretty straightforward consequence of the American election structure: the winner-take-all electoral vote and district system basically guarantee a two party system at the national level. Or, at the very least, seem to guarantee its perpetuation once established. I posted something about this in the Tea Party discussion. In European&other parlimentary systems, you often get proportional representation (Wikipedia has a good article here: http://en.wikipedia.org/wiki/Proportional_representation#Methods_of_proportional_representation) with the consequence that minority votes end up resulting in a few political seats at the national level. Once a smaller party gets a little power and influence it can then keep its issues and views in the conversation. Third parties in the U.S. don't get to take this step...