It's a crisis because the ratio of workers to retirees has been almost flipped on its head. by 2030 two individuals payroll taxes (SSI, medicare) are supposed to support each retiree, down froma opstware ratio of about 16 to 1. That means either benefits have to be slashed, or taxes on the employed have to soar. In practice there's a bit of both and more savings from reducing waste, but there's still a big gap to close. The boomers were a big generation, but they had far fewer children than their parents and lived far longer. This is a pattern that has already appeared in many other countries.

You'll see movement on immigration reform this year, because it offers the best way of correcting these imbalances without massive tax hikes or benefit cuts, and and can get us through the hump to a longer-term population equilibrium after 203 or so. See this elegantly-explained summary of the issue: http://www.ssab.gov/documents/immig_issue_brief_final_versio...