A few years ago, many of the rational thinkers were gainfully employed in a rocking economy. They were too busy creating value for others and making money to pay much attention to Krugman or his critics. That was more or less sidebar entertainment for die hards.
Additionally, while the Democrats were out of power, Krugman could spout what he wanted without consequences. There was no way of validating whether his solutions worked.
But, then the bad economy happened. Some rational people were put out of work. They have some extra time on their hands. They started looking around at the changes happening, they started teaching themselves some basics and then they started getting more vociferous at looking at the bad reasoning like much of Krugman’s, especially reasoning that seemed to be producing negative consequences.
Change brings in the new crowd to put Krugman’s thoughts to the test. The rational folks with more time on their hands start to get a bead on what’s going on and they start questioning the reasoning of folks like Krugman.
We seem to still be near the beginning of that trend, but it’s refreshing to see the the shifting back to rational thinking and folks to call out arguments that wouldn’t pass muster in 10th grade debate. People are starting to the realize the Emperor’s new clothes were a ruse.