From “Bush Budget Projects a Surplus by 2012,” in today’s Washington Post:

Recent estimates by the nonpartisan Congressional Budget Office suggest that it would be difficult to balance the budget if the tax cuts — a collection of rate reductions and tax credits that have reduced Treasury collections by an estimated $1 trillion since 2001 — continue. According to the CBO, a vibrant economy has indeed produced a gusher of revenue over the past two years that could help turn the nation’s $248 billion deficit into a $170 billion surplus by 2012. But if the tax cuts and other expiring tax provisions are extended, the CBO predicts, the deficit would hit $146 billion in 2012 and grow thereafter as health costs skyrocket and the baby-boom generation retires.