What is the relationship between tax revenue and government expenditures?

During the fiscal year of 2010, US government spending totaled $3.46 trillion. In the same year, the government collected $2.16 trillion in taxes.

43% of the federal budget went to Social Security, Medicare and Medicaid, 20% of the budget went to the Defense Department, and the other 37% was reserved for mandatory fees.

The breakdown of tax revenue is: 42% from Income Tax, 40% from Social Security and Social Insurance, 9% from Corporate Income Tax, 3% from Excise, and 6% from miscellaneous taxes.