Jonathan Bernstein has an interesting post about why Republicans keep saying such crazy things about the budget. he decides they're against the whole notion of budgeting, which I agree with. But his attempt to understand their thinking devolves into relativism about a subject that needs to have some absolute boundaries:

To characterize conservative talk about revenues and spending, I think what I'd say is that conservatives believe that each program, and every tax, should be judged on its own merits. If a spending program is necessary, like missile defense, then it should be fully funded. If not, it should not be funded. On revenues, the justification for any sort of taxation is that citizens should have "skin in the game," and therefore everyone should pay the same, small amount. Any more taxes, and any more spending, are by this way of thinking fiscally irresponsible.

Now, you may note at this point that there's nothing in that formula to make government revenues equal government spending. As far as I can tell, that's correct; conservatives aren't interested in that question. Oh, there's plenty of lip service about "budget deficits," but the point is that they've never made sense if you read "budget deficit" as "government revenues minus government spending."  It does, however, suddenly make sense if you translate "budget deficit" to mean "unwarranted spending or taxes." Regardless, that is, of how changes in that would add up.

That's why the whole concept of a fiscally sound bill that involves new spending on health care is nonsensical to conservatives who believe that individual health care just isn't the job of the federal government, a conclusion that liberals find baffling. Yes, in the trenches, some Republicans have made specific arguments about why the CBO score is wrong. But you can tell, I think, that their hearts aren't really into it—or at least, that would explain the poor quality of some of their arguments, such as the idea that the cost of "doc fix" somehow or another is both a cost of passing and of repealing ACA. Whatever, they seem to be saying; why are we even debating this, when it's self-evident that increasing the scope of government responsibilities to include some form of universal health care, even if it's structured by creating markets, is a mistake. 

That still doesn't excuse shenanigans like 10/6, which is just factually wrong. And, of course, it doesn't mean that Republicans are correct. And it certainly doesn't excuse actual deficit hawks, people who really do want government receipts to equal government expenditures, from mistakenly believing that folks like Paul Ryan are their allies. All it means is that, when listening to liberals and conservatives debate the budget, remember that they're often talking past each other—because, I strongly suspect, they're just using the same words to talk about two different things.

In some sense he's correct. Except, of course, the liberal definition of "deficit" as "the difference between revenues and outlays" is actually, you know, correct, and the conservative meaning ("government programs conservatives don't like") is incorrect. This isn't one of those "What is art?" kind of questions. The answer is pretty clear-cut.