Via Ezra Klein. The five main causes of the budget deficit are the economic downturn (tax revenues go down), the Bush tax cuts (which quickly become the largest part of the deficit), the wars in Iraq and Afghanistan, and the stimulus plan (though that becomes meaningless in less than two years, as it's being phased out).
So for the rest of this decade, the biggest single factor contributing to the deficit are the Bush era tax cuts that the Republicans say are off the table (meaning, they won't discuss getting rid of them). But just as importantly - guess what? - Obama isn't responsible for the deficit. The GOP is, along with whoever got us into those wars in Afghanistan and Iraq (oh right, that would be the GOP), and whoever was in charge of the government when the economy tanked (right again, George Bush). Oh, and a little of the deficit was caused by TARP (Bush again).
