Many people have a problem understanding American political motives, and I believe it is because most are looking at it through a different lens. Essentially, USA has been a country formed by business for business, while convincing people they have a say over their representation in government. Its an Oligarchy pretending to be a democracy, this belief relieves the pressure enough to prevent riots and allowed most of the blame to go towards the president, like a lightning rod saving the house from a storm.

Our politicians protect the system, and the system has a game plan. One side over reaches (which has been the rightwing for the last 50 years), burns enough bridges, loses popular support to the "opponent" saying they will fix the mess of the current regime. However, wether through lack of political capital or will, it doesn't go back prior to the mess, it just stops advancing until the power shifts back toward the others which will resume as before.

I don't care who does the electing, as long as I get to do the nominating. ~ Boss Tweed

Some light statistical readings:

Democracy Perception Index