One of the biggest fallacies ever committed in modern American politics is the fallacy of Centrism, a political ideology that seeks the "middle ground" between different political ideologies. This fallacy has been perpetrated primarily by moderates, who are merely centrist in disguise. Centrism is a fallacy in American politics because within the framework of American politics, Centrism can never work.
By definition, Centrism is the 'happy medium' between extremes, an attempt to not merely compromise between different political ideologies, but actually amalgamate their views to produce more excellent results. It is a very Hegelian in its dialectal approach to things: take the thesis and the antithesis and merge them into a synthesis. Such a political ideology is actually quite ideal for any society, if you live in a society with merely different political views.
It is in that last point that Centrism fails in American politics, for American politics contain only two dominant political ideologies (Liberalism and Conservatism), and they are not different; they are oppositional, i.e., they claim their views to be true and the views of the other to be false, not different. There is no middle ground between the two, no commonality between them that can even begin to serve some sort of open dialogue. Their views of government (big government vs. limited government), economics (socialism vs. free market), and nationality (democracy vs. republic), amongst other things, are irreconcilable, and any attempts to reconcile them are asinine. The "Gang of 10/20" legislation during the summer is a prime example of the futility of trying to arrive at middle roads between oppositional views. You get lame duck legislation, useless pieces of paper that effect nothing.
The sooner we stop this wimpy "let's all get along" attitude, and return to the hard truth that, in American politics, someone is truly wrong and the other truly right, the better. Compromises between polar opposites produces only inaction, as there is no way to satisfy their views without cancelling each other out.