Democrats in Charlotte are pounding away at the savage budget cuts that Mitt Romney and Paul Ryan supposedly favor and their phantom plan for "raising taxes on the middle class," as President Obama puts it. The truth is the opposite, but table that for a moment. The President seems not to realize his critique is really a scorching if implicit indictment of his own time in office.

Think about his logic like this: Mr. Ryan's House budget details a long-range plan to equalize spending and tax revenues without—ahem—raising tax...