Barack Obama has upset a lot of Democrats by bringing social security back into presidential politics. Paul Krugman of The New York Times is leading the charge. In Mr Krugman’s view, following the administration’s clumsy and aborted effort to reform the system – Democrats would say destroy it – leaving well alone makes best political sense. Mr Obama, sounding like a fiscal conservative, warns that retiring baby boomers are pushing the programme into the red and something must be done. He is, says Mr Krugman, being played for a fool.