There is a way to tally the effects Obama has had on the deficit. Look at every piece of legislation he has signed into law. Every time Congress passes a bill, either the Congressional Budget Office or the Joint Committee on Taxation estimates the effect it will have on the budget over the next 10 years. And then they continue to estimate changes to those bills. If you know how to read their numbers, you can come up with an estimate that zeros in on the laws Obama has had a hand in.