What does it mean to be "anti-deficit"? One thing the current impasse has made crystal clear is that the two parties mean something entirely different when they use that phrase.

And this is an overlooked reason a deal is so hard to reach.

Republicans appear to be entirely indifferent to budget deficits as conventionally defined by comparing federal government revenue to expenditures — but they are adamantly opposed to deficits on a symbolic level. Democrats, on the other hand, oppose budget deficits and actually do support substantive policies to shrink or eliminate them.

For Democrats, this represents the triumph of Kent Conrad, the senator from North Dakota who has long made budget-balancing his top priority. Now, all Democrats are like Kent Conrad. Barack Obama made health-care reform a lot harder by insisting that it reduce the deficit, and now he's willing to give up other Democratic priorities to get a large deficit deal. But it’s not just him. The (very liberal) Congressional Progressive Caucus budget this year was a fiscally conservative, deficit-busting document.

Republicans were once serious about deficit reduction — until supply-siders persuaded Ronald Reagan to join them in placing a higher priority on tax cuts and economic growth than on balanced budgets. The deficit has only receded as a concern since then, as supply-siders have now been displaced by anti-tax absolutists. Republicans then adopted a war on budgeting along with a very strong symbolic war on deficits, complete with symbolic policies — such as opposing increases in the debt limit and supporting a Balanced Budget Amendment to the Constitution. Sure, some Republican policies – namely spending cuts for programs Republicans oppose – would contribute to smaller deficits. But in reality, when faced with a choice, mainstream Republicans almost always prefer larger deficits to tax increases or spending cuts on programs they support.

Three comments are in order. First: There are dissenters on both sides. There are still quite a few Democrats who don’t really care about deficits, and a few Republicans (Tom Coburn is, I believe, one) are real deficit cutters.

Second: For whatever reason, professional deficit hawks have chosen to remain neutral between the two approaches, acting as if each is equally legitimate. In practice, that tends to reinforce a situation in which deficits are nominally seen as very important, but are also hard to actually solve.

Third: Compromise between the two positions is difficult. The two sides are frequently talking past each other, because Democrats and Republicans both see themselves as anti-deficit but mean completely different things by that. Worse, symbolic anti-deficit ideas typically floated by Republicans (balanced-budget amendments, failing to raise the debt limit) often would have the effect of actually increasing the federal budget deficit.

Of course, there are many other reasons the parties find it hard to reach agreements on budget matters. But one key reason not to lose sight of is that they simply mean different things when they say they're anti-deficit.