Krugman, a Nobel Prize winner in economics, has frequently criticized Obama's economic positions from the left, and has been a particular critic of Geithner's. Many expect White House Chief of Staff Jack LewJack LewMnuchin wants ‘clean debt-ceiling’ bill Conservative Republicans' bill seeks to take bite out of debt ceiling How Trump's Treasury chief can handle the debt ceiling like a pro MORE to be picked as Geithner's replacement.