Assuming Your Conclusions
A recent Washington Post news story describing a speech by Christina Romer, the outgoing chairman of the Council of Economic Advisors, provides a nice example of how to implicitly assume your conclusion. The author writes:
At week's end, Romer will leave the council chairmanship after what surely has been the most dismal tenure anybody in that post has had: a loss of nearly 4 million jobs in a year and a half. That's not Romer's fault; the financial collapse occurred before she, and Obama, took office. But she was the president's top economist during a time when the administration consistently underestimated the depth of the economy's troubles - miscalculations that have caused Americans to lose faith in the president and the Democrats.
The implication, reinforced elsewhere in the piece, is that the Democrats did the right thing, just not enough of it. Their only mistake was not making the stimulus even bigger. If only they had spent even more and taxed even less, the economy wouldn't be in such miserable shape.
That is one possible interpretation of what happened. Another is that Romer is like a medieval physician explaining to the grieving relatives that if only he had bled the patient a few more times, he would have recovered. One way to judge a scientific theory is by comparing what it predicts to what happens. One of Romer's predictions was that unemployment would peak at 8%. It didn't. I do not know whether Romer has considered the possibility that the reason her prediction was wrong was that her theory was wrong, but pretty clearly the author of the piece has not.
He merely takes for granted the Keynesian orthodoxy of fifty years ago, according to which the right way of dealing with a recession is to run a deficit, and the worse the recession the bigger the deficit should be. The administration followed that prescription, things didn't get better, so obviously the deficit was not big enough. The alternative possibility, that the reason things didn't get better might be that they were following the wrong policy, simply didn't occur to him.