Nitpick: I believe that defense is discretionary and medicare is mandatory. The distinction is a bit phony though, since congress can change mandatory spending by statute, and Congress has only limited real maneuvering room to radically alter the Federal workforce (discretionary) from year to year.
I agree, the distinction is totally phony. The whole purpose is to allow the two sides to talk about cutting spending without talking about politically impossible spending cuts - without admitting that they aren't talking about most of the spending.
http://www.weeklystandard.com/blogs/over-60000-welfare-spentper-household-poverty_657889.html
60000 dollars per year per poor family, if the article is correct.