Pretty much everything you need to know about President Obama and the budget deficit is contained within this chart:

The chart, which is based on Congressional Budget Office figures, shows something which is both incontrovertible yet known by very few people: Obama's budget does not increase the long-term, or even the medium-term, budget deficit. It reduces it slightly. Most of the commentary castigating Obama for the deficit is an attempt to imply, usually without quite saying so, that Obama's policies have caused the red ink. This editorial from National Review is typical:

federal fiscal policy has now run completely off the rails... what had been a chronic problem that all involved knew needed corrective action has now become, in the Obama years, a full-fledged disaster in the making.... If the Obama budget is adopted in full, federal borrowing will top $18 trillion by 2020. Over the period 2011 to 2020, the president’s plan is to run deficits totaling an astounding $8.5 trillion.

Based on the writing of this editorial, NR's editors know full well that Obama's budget does not cause the fiscal disaster. They are blaming him for failing to clean up the mess he inherited. That's a fair thing to blame him for, but it's not a serious enough crime to sustain the rhetorical fury. So the NR has written the editorial in such a way as to lead its readers to the erroneous conclusion that Obama has caused the deficit. It's true that "If the Obama budget is adopted in full, federal borrowing will top $18 trillion by 2020." What the editorial fails to say is what will happen to federal borrowing if Obama's budget is not adopted. We are supposed to think that the debt will be lower, but it won't. It would be higher.