Compare this back to 2000, when income taxes made up 50% of revenue and payroll tax made up 32%. The amount of income taxes collected in 2010 dropped 106 billion from 2000, while the amount of payroll tax increased by 215 billion.

During that time, social security ran a surplus of roughly 500 billion dollars.

Nice.

Source

http://www.census.gov/compendia/statab/cats/federal_govt_finances_employment.html