The Congressional Budget Office recently projected federal debt over the coming decades — assuming that current laws remain in place — and then asked what would change, given all-too-plausible variations around its customary baseline. It found that the ratio of debt to GDP, already at a postwar high of roughly 100%, is on track to exceed 150% over the next few decades. If the path of future interest rates is higher than assumed — increasing by 5 basis points a year — the debt ratio will exceed 200%. And if, instead of conforming to current law, revenue and spending maintain their historical averages (discretionary outlays of 7% of GDP and revenue equal to roughly 17% of GDP), the debt ratio will exceed 225% in 2050. (By 2055, it’s literally off the chart.)