I was going to write a long post on Krugman's article, but Michael Cannon takes care of it with one sentance:
Paul Krugman says libertarianism is not a serious political philosophy because politicians are corruptible, do stupid things, et cetera. My colleagues Aaron Powell and David Boaz demonstrate why that's a bigger problem for Krugman than for libertarians: Krugman's statism wouldn't make politicians any less ignorant or corruptible, it would just give those ignorant and corruptible politicians more power.
By the way, I thought this earlier article by Brett Barkley was pretty interesting. He investigated which economists changed their views the most based on who occupied the White House. Want to lay any bets on who won the title of most politicized economist?
When the White House changes party, do economists change their tune on budget deficits? Brett Barkley does a systematic investigation. Six economists are found to change their tune "“ Paul Krugman in a significant way, Alan Blinder in a moderate way, and Martin Feldstein, Murray Weidenbaum, Paul Samuelson, and Robert Solow in a minor way "“ while eleven are found to be fairly consistent.