To be fair, I'm not so sure this wouldn't happen with a >2 party system, either. Factions would still have to group together into a coalitional government if they wanted to get anything done. And then there's still no guarantee that anything would get done. Sometimes the presence of an extra label in and of itself suppresses cooperation as it reinforces ideological differences. e.g. the already present schism w/in Republican circles between moderate ("moderate") Republicans and Tea Party conservatives. If you think the Republican party is any more ideologically monolithic than the Democratic party (or even AS ideologically monolithic), you nuts, _refugee_.

Come to think of it, I bet you could make a strong case that we already have a >2 party system. Tea Party & traditional Republicans is more an arranged marriage than a romantic marriage. And there are increasing striae w/in the Tea Party contingent as well, between social conservatives and more traditional right-leaning libertarian types and just flat out crazy people (used to work with a lady that believed she could talk to her cats- she was a proud part of the original Tea Party demonstrations). (That was a low blow but it felt good.) So maybe we're just seeing concurrent greater divisions inside the left as well- everybody's pulling apart. More and more parties attempting coalition under increasingly superficial umbrella labels. Personally, I think it's not so great.

In the late nineties, some scholars argued we didn't even have a 2 party system, but rather a 1.5 party system, wherein the differences between the American left and right were less pronounced than elsewhere, and the American public tended to stray towards the center, where the divisions were even fuzzier. Each side talked a lot of game, but both made ideological concessions behind closed doors for the sake of their constituencies and ultimately things trended towards the center. Now what, earmarks have become a dirty word (or are they technically illegal now?) providing disincentive to compromise, legislative fights have become so public and pronounced that nobody can grant any concession for fear of looking like an ideological traitor, huge moneyed interests have put their resources behind the principle of shrinking gov't small enough to "drown in a bathtub," etc. More parties now, less getting done.

Forgive the poor writing, I'm tired and no coffee and bluuuuurgh