As far as former President George W. Bush being blamed for a "[$]4 trillion[]" rise in the national debt in eight years, the total public debt outstanding on January 22, 2001 (two days after Bush's inauguration) was $5.7 trillion. The same figure for January 20, 2009, as previously mentioned, was $10.6 trillion, an increase of $4.9 trillion.
In the monthly CBO report on the budget for January 2001, the gross federal debt was projected to have a year-over-year decrease for the first time in decades beginning in 2001 and continue a year-over-year decrease until 2006. Of course, that didn't happen.