I suppose that’s because money collected for Social Security was counted as income, even though it was invested in US bonds. They add to the debt, but aren’t counted in the budget as a deficit. Cute trick.
Just wait until the 70 trillion in unfunded entitelments begin to come due in the next decade. You ain’t seen nothin’ yet.
Interestingly enough though, 30 year treasuries are about 4% or so reflecting a belief that we will be able to pay those entitlements (or figure out some way to reneg) along with growing the economy (and tax revenue) enough to pay off the bonds. We also know there is a man behind the curtain (Bernanke) jerking rates around with quantitative easing. But if those rates were really a reflection of the market, the market would be saying that American voters are going to replace the socialists and elect pro-growth politicians.
That makes for an interesting bifurcation, we will either succeed spectacularly or fail spectacularly and it's up to the voters.