There is a very revealing point in this video (around the 3 minute mark) where Senator Simpson rails against Paul Krugman. He says “you don’t have to have a brain” and proceeds to prove it. He is trying to make the point that the frightening-sounding statistics he cites trump the arguments of a brainy Nobel-prize-winning professor. (Of course, Simpson’s statistics are irrelevant to Krugman’s arguments.) I think this gets to the heart of our political problem. There are those in policy-making positions who believe their ‘common sense’ or their ‘gut’ trumps years of study, Nobel Prizes, textbook economics, or even economic reality (viz. David Cameron). They may find it obvious that if there is a record snowstorm outside their window that global warming must be a hoax. I suspect that some of them may still ‘know’ that of course if you drop a cannon ball and a baseball from the Tower of Pisa the cannon ball will fall much faster.
Experts, expertise, and evidence are not infallible. Even the scientific conventional wisdom can be wrong, especially in the social sciences. But like the old trope about democracy, expertise is the worst foundation for effective policy except for all the others that have been tried. Skepticism is fine, but the rule of ideology and ignorance can lead us to disaster.