The scholars found mixed results. Medicaid does lower psychological stress and increase financial stability, results we would expect from any transfer program. But the program actually increases unnecessary trips to the emergency room. And remarkably, Medicaid coverage has no measurable impact whatsoever on clinical health.

To an intellectually honest observer, these findings compel more questions. What are reasonable expectations for health insurance? Should we be satisfied if Medicaid helps people sleep easier but makes them no healthier? Even if so, is health insurance the most effective way to convert taxpayer dollars into peace of mind for the poor?

Virtually no prominent progressives join center-right commentators in positing such questions. In a recent Intelligence Squared debate over the ACA, the liberal commentator Jonathan Chait laughed all these studies by feigning surprise that—gasp!—disproportionately impoverished Medicaid patients might be unhealthier than average folks. The problem, of course, is that every study worth its salt controls for demographics and income. Many of the Medicaid studies even control for existing health status. But never mind the facts—favorable news is trumpeted, negative results are brushed aside, and conventional wisdom marches on.