The core trait of a scientific mind is that when its commitments clash with evidence, evidence rules. On that count, what grade do liberals deserve? Fail, given their reaction to the latest evidence on universal health care, global warming, and universal preschool.

The policy world was rocked recently by a New England Journal of Medicine study showing that Medicaid doesn’t improve the health care outcomes of uninsured individuals. …

How should a scientifically-inclined liberal have reacted? By acknowledging that if the findings hold in subsequent years, Obamacare’s plan to use Medicaid to achieve its universal coverage goal — at half-a-trillion-dollar price tag over a decade — would need to be reconsidered. …

And how have liberals reacted? By sticking their fingers in their ears and chanting la-la-la.