Chad Kolton, a spokesman for the White House Office of Management and Budget, said Bush was on track to cut the deficit by half over the next five years. "We have a two-pillar approach for getting the budget deficit down by half," Kolton said, "by restraining the growth in government spending and encouraging greater economic growth that leads to higher tax revenues."

But even if rising tax revenues do help reduce the deficit over the next five years, the subsequent five years are likely to be far more difficult.

For starters, Bush wants to permanently extend his tax cuts rather than allow them to expire by 2011. That would cost about $1.8 trillion over the next decade, and most of the cost would occur in after 2009.

If Congress prevents an expansion of the alternative minimum tax, which Bush has said he wants, the cost would be $500 billion over the next decade and well over half of those costs would in the second five years.

Those blows would be hitting the budget at the same time that the costs of the new Medicare prescription drug programs approach $100 billion a year and as the flood of baby boomers start to claim Social Security and Medicare entitlements.

By that time, however, Bush will no longer be in office.

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Contributing: Martin Crutsinger, Associated Press