two reasons. 1. Their funding doesn't come out of discretionary spending, they self fund through individual taxes. 2. Their outlays go mainly to older people

two reasons. 1. Their funding doesn't come out of discretionary spending, they self fund through individual taxes. 2. Their outlays go mainly to older people who have a tendency to group in specific states, and due to the size of the expenditure relative to the rest of the budget even a small bias in where that money goes overshadows any real variance in discretionary spending