Right now the revenues from the payroll tax exceed the amount paid out in benefits. This is deliberate, the result of a payroll tax increase - recommended by none other than Alan Greenspan - two decades ago. His justification at the time for raising a tax that falls mainly on lower- and middle-income families, even though Ronald Reagan had just cut the taxes that fall mainly on the very well-off, was that the extra revenue was needed to build up a trust fund. This could be drawn on to pay benefits once the baby boomers began to retire.
The grain of truth in claims of a Social Security crisis is that this tax increase wasn't quite big enough. Projections in a recent report by the Congressional Budget Office (which are probably more realistic than the very cautious projections of the Social Security Administration) say that the trust fund will run out in 2052. The system won't become "bankrupt" at that point; even after the trust fund is gone, Social Security revenues will cover 81 percent of the promised benefits. Still, there is a long-run financing problem.
But it's a problem of modest size. The report finds that extending the life of the trust fund into the 22nd century, with no change in benefits, would require additional revenues equal to only 0.54 percent of G.D.P. That's less than 3 percent of federal spending - less than we're currently spending in Iraq. And it's only about one-quarter of the revenue lost each year because of President Bush's tax cuts - roughly equal to the fraction of those cuts that goes to people with incomes over $500,000 a year.
Me, I'd fund this directly through bringing back the estate tax. It could be done very easily, and have no effect on those much touted "family businesses."