It's both revenues and spending, technically, but while revenues have gone up and down, spending has ALWAYS gone up.

I posted the budget history on my blog a while back. There are newer tables for 2012, but the numbers for past years are either identical or very close.

Follow the numbers in constant 2005 dollars. You can see that spending increases steadily, while revenues are less steady. Revenues rose to a peak of $2.31 trillion in 2000, creating a surplus. Outlays were about $2 trillion when Bush took office. The revenues were not about high tax rates. They were from a huge economic boom (however temporary). A lot of people got very rich at the end of the 90s.

The recession and 9/11 dropped the economy and revenues. For the first part of the Bush administration, revenues dropped but spending still increased rapidly. Revenues began climbing again in 2004, but by then the deficit was $428 billion. Sounds so small now, doesn't it? But it's a horrible deficit by any standards. Revenues kept climbing, and deficits began dropping, but again spending still went up from one year to the next. Revenues hit an all-time high of $2.41 trillion in 2007, $100 billion more than the previous 2000 peak. But the deficit was still $151 billion. Spending had outrun the revenues.

Note that this $2.41 trillion revenue in 2007 - under Bush's tax rates incidentally - would have resulted in a surplus for every previous year except 2005 and 2006. That's how fast spending rises.

Then another recession, and revenue drop. Note that tax rates had not changed. Revenues in 2009 were down to $1.9 trillion. And spending STILL kept shooting up. Note that this miserable recession revenue would have still produced a surplus for every year prior to 1996. At the end of 2008, spending was over $700 billion higher than when Bush took office eight years before that.

In 2011 - only three years later - outlays will be about $3.4 trillion. $670 billion higher than 2008. Plug in the historical record revenue of 2007 and now you get a deficit of almost $1 trillion. Plug in the great revenues of 2000, generating surpluses, and the deficit would be $1.1 trillion.

Again, all of these are constant 2005 dollars. I hope I didn't screw up any math, but the table is there for you to look at and draw your own conclusions.