Unlike most government programs, Social Security and, in part, Medicare are funded by payroll taxes dedicated specifically to them. Some of the tax revenue pays for current benefits; anything that's left over goes into trust funds for the future. The programs were designed this way for political reasons.

Of course, plenty of people don't think that guaranteeing affordable health insurance is a core responsibility of government.

Politically speaking, it's always easier to shell out money for a disaster that has already happened, with clearly identifiable victims, than to invest money in protecting against something that may or may not happen in the future.

James Surowiecki Quotes