That's a great graph - really shows how things changed under the various presidents.

As has been documented many places, Bush did three things to skyrocket the debt from $5.7 trillion to $10 trillion:
1. He lowered taxes on the rich (by far the biggest item).
2. He invaded Iraq instead of winning in Afghanistan-Pakistan (another $600 B).
3. He loosened controls on Wall Street.
Interestingly, McCain backed all three policies. Obama didn't.