From the Rolling Stone interview with Paul Krugman:
But you need to have some perspective on the seriousness of this whole thing. On the day the trust fund is exhausted, Social Security revenue will cover about eighty percent of the cost of benefits. Right now — today — if you look at the U.S. government outside of Social Security, revenue covers only about sixty-eight percent of total government spending. So on the day the trust fund is exhausted, forty-seven years from now, Social Security will be in better financial shape than the rest of the U.S. government is today.
…It’s hard to understand why anyone would want to return us to the days before the New Deal, when millions of elderly people lived in poverty. But if you really dislike the notion that the government provides a safety net for the poor, then Social Security is the prime target. The U.S. government is a big insurance company, with a side business in national security. Social Security is the biggest social-insurance program that we have. It’s been highly successful, and it’s extremely popular. It’s one of the things that makes people feel somewhat good about government — and so, therefore, it must go.