It can be entertaining or disturbing reading letters from the folks who think Paul Krugman is the devil. I can see why partisans could get angry at his column. It is, after all, titled Conscience of a Liberal. I would invite you to go to The New York Times and start reading his daily blogging instead. These (usually) short posts will often show you the development of a column or idea in a more reasoned way.
The laws/science/voodoo of economics, just like those of nature, do not have a conscience or a moral code. They do not reward the good or punish the bad. Those are distinctly human desires. So what really counts when looking at how economic choices affect policy decisions, what is best on a macro level, is using what evidence you can gather, what facts are telling you, and ones expertise of thought in a field in which you have a track record. As Prof. Krugman will tell you, a shiny medal doesnt mean a lot. A track record does. Perhaps the doubters should try to pay attention to his rationale rather than politics.