You don't go from Bush's $1.5 trillion deficit to a $0 deficit overnight.
Bush rapidly increased the
rate of increased spending. Obama has been decreasing that rate.
No matter who was President after Bush, they would be facing a doubling of the federal debt because of how much BushCo increased deficits.
It's a fact that deficits decreased every fiscal year Clinton was in office.
It is a fact that deficits skyrocketed to historical levels under Bush.
No only that, Bush set a record deficit, and then broke his own record, tripling it. So of course his successor was going to have a helluva job getting the deficit back down to normal levels.
Obama has reduced the deficit every fiscal year.
You can see these facts for yourself
here and
here.