This chart represents the U.S. discretionary budget - for last year. It does not include the bailout or the massive increase Congress voted overwhelmingly to give the Pentagon for this year.
The first limitation needs to be on defense spending; i.e. the stupid wars in Iraq, Afghanistan and marginally Pakistan.
There's something radically wrong when we're spending this proportion of our national budget for oversees military operations - and we have the pressing economic/social catastrophe here at home.