A trillon of that was paying Bush's TARP, another trillion was Bush's Afghan and Iraq wars. Another trillion was Obama's Stimulus, which should not have been done - States who betted their money on Wall Street and eventually lost it should have fed their losses to their people.
Other than that, spending rate of increase under Obama fell to the lowest since the end of WWII. He had the dollar strengthened as well, which Bush deliberately weakened to help pay for his unpaid for inceases.
Jus sayin,,,