His great crime-—and it is a great one-—is damaging the integrity of the scientist with hateful political opinionizing. Traditionally, scientific opinion was respected because of limits on the opinionating of the scientist and the scientist’s wisdom not to venture into realms outside his professional area of study to editorialize and divorce himself from objectivity. Krugman wallows in public opinions that are not grounded in sound economic theory or evidence. It is emotion—not the currency of a good scientist. All scientist’s motives are made less respected when such an individual is held up as the greatest of scientists. His scientific legacy will be colored by such activities.
But yet none of that was why he was awarded the Nobel. Back to the issue at hand, his work on international trade. That work is well done and deserving of the award.