The Bush tax cuts passed in 2001 and 2003 were intended to return the surplus that existed in 2000 to the taxpayers and to stimulate the economy. I am sure that the tax cuts have eliminated the surplus many times over and we now have a tremendous deficit. The evidence is that tax reductions, especially those that go primarily to wealthy people, are not effective in stimulating the economy and that was certainly true with these cuts.
If it was proper to lower taxes because there was a budget surplus it follows that when there is a deficit, the corresponding course is to increase taxes. Or, in this case, let the tax cuts expire. The reason for the tax cuts no longer exists. Isn't that straight forward?
What amount of revenue is involved anyway? It isn't easy to find an estimate. One source estimated the reduction in revenue in 2004 at $276 billion. But despite numerous articles about the effects of the tax cuts on revenue, figures are just not included. One reason is that there is no fixed figure. The tax cut itself becomes a factor and other factors come into play. There are arguments made that tax cuts actually increase income tax revenues, counter-intuitive as that seems. It is certainly possible that if taxes are cut modestly when the economy is growing robustly income tax revenues could increase because there would be more income to tax. The argument is, in fact, that tax cuts stimulate the economy and that provides more income to tax. The evidence seems to be that any stimulus effect is small at best.
The figures I did find about income tax revenues were from Christopher Chantrill (who describes himself as a conservative) at www.usgovernmentrevenue.com. For the years 2000 through 2010 he lists income tax revenue (in billions) at $1,212, $1,145, $1,006, $976, $998, $1,206, $1,398, $1,534, $1,450, $1,054, and $1,093. For those same years he shows the surplus (deficit) (again in billions) as $236, $128, ($158), ($378), ($413), ($318), ($248), ($161), ($459), ($1,413), and ($1,556). I don't know whether the surplus/deficits after 2001 include the costs of the wars in Afghanistan and Iraq.
Assuming that income taxes would normally increase 5% annually (and I have no basis for that assumption), then, taking the 2000 income tax revenue as $1,212 billion, the expected revenue for 2004 would be $1,473 billion. The actual revenues of $998 billion would mean a reduction in income tax revenues in 2004 of $475. There was a recession in 2001 and there is no question that recessions after a depressing effect on income tax revenues. So the estimate of $276 billion in lost income tax revenues in 2004 as a result of the tax cuts may be in the ball park.
Letting the Bush tax cuts expire might result in increased income tax revenues of about $275 billion each year. That would have led to roughly balanced budgets until 2009 when the deficits soared. But the question still is, what possible reason can there be to extend those tax cuts?