Well, those predictions are made using the forecasting models at the BEA, CEA, and Fed. So he has to be making some progress or the models won't show any improvement.
The result? He's cut the deficit from $400 billion in 2004 to $250 billion in 2007. Then again, the new stimulus package is
exactly $150 billion, which nulifies all the progress we made in the last three years.
But yes, the hard part will be reducing the deficit in the next four years, with a weakened Fed and shaky economy. The next guy has his work cut out for him.