In the column, Axis of Depression, Paul Krugman explains the real motives of the Republicans.

So what’s really motivating the G.O.P. attack on the Fed? Mr. Bernanke and his colleagues were clearly caught by surprise, but the budget expert Stan Collender predicted it all. Back in August, he warned Mr. Bernanke that “with Republican policy makers seeing economic hardship as the path to election glory,” they would be “opposed to any actions taken by the Federal Reserve that would make the economy better.” In short, their real fear is not that Fed actions will be harmful, it is that they might succeed.

If this isn’t another perfect example of Greenberg’s Law of Counterproductive Behavior, then I don’t know what is.