The deficit is basically about the depressed economy.
Read the whole thing if you don't know this.
Because poilticians know this. And if they are counting on you not knowing this to pull the wool over your eyes and fulfill their austerity aspirations on the basis of ignorance of the budget, that's a problem.
It is much easier to make the austerity case to the public when there is a big deficit, even though (1.) a deficit is good right now, and (2.) the size of the deficit has nothing to do with the "size of government" philosophical issues they care about.