Volatility.

As I went over the numbers over the past year or so, I came to realize that Federal surpluses and deficits were not so much a matter of tax rates (as popular mythology would have it) as they were of basic economic prosperity and business successes and failures. The research in this article confirms this.

To put it simply, we got a surplus in the late 90s because a lot of people were getting very rich in the tech boom. It dropped off when the boom did.

The GDP of twenty years ago could not support the government spending of today. Federal spending now is twice what it was in 1988 (constant dollars) yet the percentage of GDP of Federal spending is only five percent higher than it was then. That we aren't in worse shape than we are is because of real wealth creation, not wealth redistribution.