This chart [1] from CNN/Money projects that in just 9 years, fully 92% of the federal budget of the United States could go to just 4 things: Medicare, Medicaid, Social Security and interest on the national debt.
Picture this: the entire American government as one big wealth redistribution engine.
Actually, you don't have to imagine it. Seriously, check out this truly awful imagery [2].
Links:
[1] http://money.cnn.com/news/economy/storysupplement/spending_pie/
[2] http://money.cnn.com/news/economy/storysupplement/spending_pie/