One of the underrated impediments to a debt ceiling hike is the Republican belief that any agreement with President Obama is by definition a bad one. Part of this is the rational partisan urge to deny Obama a big accomplishment he could use to position himself for 2012. Another is a simple heuristic. Budget agreements are convoluted and require assumptions about how present agreements will bind future actors. If you consider Obama a socialist, then anything he agrees to by definition can't be a moderate deficit-cutting program to reduce government.

Obviously, we can't get into the heads of various Republicans and suss out their mental processes. But you can almost prove that this phenomenon is occurring via a simple thought experiment. Obama has signaled his support for at least two major deficit-reducing agreements. When presented with these plans, conservatives have two major decisions to make. One is, does this constitute a genuine (or supportable) deficit-reduction program? And two, is Obama's support for it genuine?

In theory, these would be two separable questions. You could map out conservative reactions into four boxes, representing the four yes/no positions on those two questions. In reality, conservative reaction has broken down into just two positions. You have those who dislike the plan while agreeing that Obama supports it, and those who like the plan in question but doubt Obama supports it. The other two boxes (like the plan and agree that Obama supports it, and dislike the plan and doubt Obama supports it) appear, as far as I can see, empty.

So, for instance, when word leaked of an Obama-Boehner Grand Bargain, you had the Wall Street Journal editorial page denouncing the deal for raising taxes. Charles Krauthammer, by contrast, described the details as "offers of surpassing scope and reasonableness," but insisted they could not be real because they were being proffered behind closed doors. The Journal opposed the reported plan, which allowed it to accept reports of the plan's details, while Krauthammer liked the details, which forced him to angrily deny its existence. Other conservative commentary I've seen has fallen into these two categories.