Making economic and budget predictions is hard, especially when wars, recessions, and financial crises pop up unexpectedly. Here's the Congressional Budget Office's ten-year budget forecast from 2002 (note that this was after the Bush tax cuts were passed...
Please continue reading at:
http://www.aei-ideas.org/2012/12/in-2002-cbo-predicted-2012-u-s-debt-would-be-7-4-of-gdp-in-reality-it-was-almost-74-of-gdp/