These days, Paul Krugman is a pundit masquerading as an economist. He won his Nobel Prize for work he did in the 70s on international trade, which lends no credibility to his screeds on domestic politics.
I've read that for some years, most of the editorials published under Paul Krugman's name have actually been written by his wife, also an economist. That would explain the difference between the "old" and "new" Krugman.