The Center for Retirement Research at Boston College is funded by the Social Security Administration. It's now produced a "brief" entitled The Implications of Social Security's "Missing Trust Fund." Here's how it starts:
As policymakers consider restoring financial balance to Social Security, understanding the reason for the shortfall is important. If the cost of currently scheduled benefits simply exceeds what today’s workers are paying into the system, the traditional proposals to reduce benefits or raise payroll taxes would be most relevant. However, the cause of the shortfall lies elsewhere. Specifically, the program’s “pay-as-you-go” approach – with the exception of the recent build-up and spend-down of a modest trust fund in anticipation of the baby boom – makes the program expensive. This financing approach is the result of a policy decision in the late 1930s to pay benefits far in excess of contributions for the early cohorts of workers. The decision essentially gave away the trust fund that would have accumulated and, importantly, gave away the interest on those contributions. This brief, based on a recent paper, explores the implications of the “Missing Trust Fund.”
Basically, this is the Republican argument against the very existence of Social Security. I find reading this in a government financed report jarring. "Missing Trust Fund"? Were they trying to incite Democrats? I will say that the article goes on to say that it may be best to partially fund Social Security out of general income tax revenues which definitely is not a Republican position.