Tax reform must reduce the size and number of taxexpenditures to reduce the budget deficit and lower marginal tax rates for individuals and corporations.
Besides widening the budget deficit, taxexpenditures encourage behavior that likely would have occurred anyway or just plain doesn't make good economic sense.
Table 1 below shows Federal Tax Revenues, Federal Expenditures and the Budget Surplus or Deficit from 1993 (the first year of the Clinton Presidency) to 2011.