Jerry, the debt is not 4 trillion, it's 14.5 trillion and counting.
http://www.usdebtclock.org/
This time in 2008 it was around 10 trillion so we have seen a 4.5 trillion increase in three years. In 2000 the debt was almost 6 trillion.
It's estimated by the CBO that the debt will be almost 19 trillion by 2015 but if the current trends sustain it will be closer to 23 trillion.