Chris Cillizza takes the long view of Barack Obama’s approval ratings today and notes that what really characterizes him is stability. That’s right, and an excellent antidote for hyperventilating about every three-point dip and surge.

He repeats a theory to explain this that I’ve heard before, but I’m fairly confident that it’s wrong. Cillizza:

What the numbers tell us is that anyone with even an inkling of partisanship has been pushed into one of the two parties at this point . . . His polling ceiling and floor are very defined and, at least based on the last few years, largely unaffected by external circumstances. Given all of that, large-scale changes in how the public perceives Obama is very, very unlikely — now or at any time until he leaves office in early 2017.

The problem is that while Obama’s approval ratings have been unusually steady, George W. Bush had wild fluctuations, and both of them served during a period of extreme polarization.

The more likely explanation for Obama is that his administration has been consistently, as the kids say, meh. Most obviously, the economy: no technical recession since the first several months of the Obama administration, but nothing strong enough so far at least to make it feel like a real recovery; no growth like that in the middle of Ronald Reagan or Bill Clinton’s presidencies. Foreign policy? Certainly no Iraq-sized disasters, but the unpopular war in Afghanistan has continued, and with the exception of the death of bin Laden there haven’t been any headline-type triumphs, either. Other domestic policy? He’s passed enough items that he doesn’t seem incompetent, as Jimmy Carter or early Bill Clinton did; on the other hand, his signature accomplishment, the Affordable Care Act, isn’t very popular. And, the last few weeks notwithstanding, no significant scandals that could really tank his popularity.

In other words, it’s not that Obama’s popularity isn’t affected by external circumstances; it’s that the external circumstances have mostly been mixed signals.

If the economy really does take off; if the U.S. leaves Afghanistan without major incident and is finally at something resembling peace for the first time in years; and if the current scandals mostly fizzle out . . . then I wouldn’t be at all surprised to see Obama’s approval ratings start to edge up to second-term Clinton levels. On the other hand, if one or more of the current scandals picks up steam or if a new recession strikes, I’d expect Obama to bottom out well below 40 percent approval.

Basically, it’s a very plausible theory, but the evidence just doesn’t seem to fit.