That Krugman is too thick to see that one can’t infer anything about the quality of partisans’ reasoning from the truth or falsity of their beliefs is … another element of Krugman’s proof that ideological reasoning is symmetric across right and left!

For in fact, that “the other side” is closed-minded is one of the positions that partisans are unreasoningly committed to.

One of the beliefs that they don’t revise in light of valid evidence but rather use in lieu of truth-related criteria to assess the validity of whatever evidence they see.