Here are some sources that try to answer this. All in all, regardless of how you feel about entitlements, less money is going towards them than I expected to see.

1. Metaverse
2. Library of Economics and Liberty
3. Budget of the US Government: Historical Tables Fiscal Year 2009
4. Interesting polling data on Americans’ views on welfare
5. A bit of Pennsylvania perspective
6. Tax breaks = Entitlements

I was and still am surprised at how difficult it has been to find good information on this subject.