There probably isn't a worse job in Washington than Medicare trustee, unpaid Capitol Hill interns included. Every year the trustees issue the gravest warnings about entitlement spending and at best prompt a moment of brow-furrowing before the political class returns to its default state of indifference.

This year's report, issued last week, has more than the usual political meaning because Democrats are hailing it as validation of their claims that ObamaCare will save taxpayers money. The trustee report shows "how the Affordable...