Nearly all the growth in government spending over the past 40 years is due to growth in entitlement programs. In fact, government spending would be even higher were it not for reductions in defense spending.

I would be curious to see how much of the growth in entitlement programs is due to more people being eligible for them and ballooning healthcare costs vs. expansion of benefits of those programs.

1972 to 2011 is a pretty large timeframe. I wonder what a shorter snapshot of government spending would look like (say, the last 6 years under Obama's administration.) How different would this graph look then?