Spoiler alert: Tonight President Barack Obama will call for a "balanced" approach to deficit reduction. Republicans, their allies, and quite a few pundits will respond by saying the real problem is government spending—and that the president is ignoring it. It's what they always say. And if you don't believe me, go online and watch some recent clips from MSNBC's "Morning Joe." Joe Scarborough, the normally affable (and Republican) co-host, has been practically apoplectic about this for the last few weeks, criticizing—among others—New York Times columnist Paul Krugman, House Minority Leader Nancy Pelosi, and of course Obama himself. All of them, he says, are ignorant or pretending to be so.

Thing is, Scarborough and his ilk have a point—not about the supposed ignorance of the Obama camp, but about the deficit. We do have a spending problem. It's just not the problem that these critics seem to think. It's a very specific spending problem, one that calls for a very specific kind of solution.

To understand why, you need an up-to-date picture of the economy and federal budget—which, conveniently enough, the Congressional Budget Office produced just last week. The short-term outlook on the deficit is pretty good, all things considered: It's down below $1 trillion for the first time since Obama took office, and is expected to continue going down for the next few years. The short-term outlook on the economy is pretty mediocre: The economy should keep growing, the CBO predicts, but not very quickly. These two facts are very much related: Given the weakness of the economy, deficits for the immediate future should ideally be higher, not lower.

The fiscal problem, as the CBO explains, is what happens after the next few years. Over time, the gap between what government spends on programs and interest, on the one hand, and what government raises in revenue, on the other hand, will likely grow. The bigger it gets, the more it threatens harm. Every dollar spent on interest, after all, is a dollar spent to a bondholder rather than a dollar spent on roads, tanks, schools, and assistance. Eventually we'll have to cut back what we spend or raise taxes a whole lot more—unless we're willing to borrow much more, thereby incurring bigger interest costs and, potentially, undermining economic growth.

One way to address this problem is to start raising taxes right now. The deal Obama and Republicans made in early January, restoring rates on high incomes to their Clinton-era levels, are a good start—but only a start. That deal produced only half the revenue that Obama sought when negotiations began. And, by historical and especially by international standards, Americans still don't pay very much in taxes. Eventually taxes should rise even on the middle class, not just the poor; Obama's 2008 vow not to raise taxes on incomes below $250,000 remains one of the worst, most damaging promises he's made. But there's no point in talking about higher taxes on the middle class when the wealthiest Americans are still benefiting from so many tax breaks.