From Jed Graham at Investor's Business Daily:
By 2023, under Paul Ryan's budget, the entirety of federal spending outside of Social Security and interest on the debt (16.4% of GDP in 2012) would shrink to 11.2% of GDP, a level not seen since 1948 — before ObamaCare, Medicare, Medicaid, NASA, the interstate highway system and almost before the first baby boomers were born.
That is nearly 25% below the 14.6% of GDP average over the past 64 years. In the only three years over this span that saw spending on the main functions of government (outside of saving for retirement) dip just below 12% of GDP, the unemployment rate averaged 4.5% or less, shrinking safety net outlays while bolstering the spending capacity of state and local governments.