So when the president’s budget errs in its estimation to the tune $58 billion, why is a more invasive pursuit of taxes the obvious answer?

The Obama administration on Monday proposed $58 billion in additional taxes to offset budgeting errors that overstated revenues in the president’s plan to finance health care reform.
The tax measures target a host of activities, including people who for tax purposes aggressively reduce the value of property received as gifts or in estates. To reduce fraud, other provisions would require investors, contractors and taxpayers to provide more information about certain transactions to the Internal Revenue Service.
The largest budgeting error overstated the amount of money that would be raised by limiting charitable and other deductions for high-income taxpayers. The limits would generate $267 billion over the next 10 years — $51 billion less than the administration projected in February.

It seems that, no matter what happens — even an incident of miscalculation on the administration’s part — the government gets a little bit more power and control.