Another party will be seated in Congress soon. Americans accustomed to a hundred channels on cable are primed for at least one more voice in Washington. The traditional two party system is like the traditional two sex system. Once unthinkable, now 10% gay is the norm and has outsized influence. A ten percent third party when it comes will also have outsized voting power. Change for more choice is coming like a force of nature.
As parts of California and Colorado toy with secession, as Quebec thinks it can manage without Canada, as Scotland devolves from England, and feuding couples find they can afford to split into two households, more choice will be the future for Congress too. Smaller groups are viable because fewer layers of management are needed. (See Drucker quote below)
I don't expect the near equal split between Democrats and Republicans to change but people they serve poorly will shop their vote. This means the first third party to seat members will be a tie-breaker with outsize voting power. Disaffected voters can be drawn from anywhere but the leadership catalyst is more likely to come from the right than the left this time. The somewhat anarchic "Occupy" types camping in public parks look weaker than "Tea Party" types who show up to join party committees. Sarah Palin supporters can take heart.
Drucker: "The typical large business 20 years hence will fewer than half the layers of management of its counterpart today and no more than a third the managers". (Drucker (1988) in the Harvard Review).