President Obama's approval rating...

...is approaching its worst point ever. In the latest Real Clear Politics average, 41.4 percent of those polled approve of the job the president is doing while 55.3 disapprove. That's closing in on the 39.8/55.9 spread back on December 3, 2013.

So what gives? Why is the public so disenchanted with President Obama? Is it immigration, or the situation in Ukraine or Gaza?

When in doubt, I return to the famous words of James Carville, "It's the economy, stupid."

The Associated Press had a piece yesterday, "As US job market strengthens, many don't feel it" (my emphasis):

For millions of workers, happy days aren't quite here again.

Though the U.S. unemployment rate has plunged since the start of last year to a five-year low of 6.1 percent, the Gallup Organization has found that consumers' view of the economy is the glummest it's been in seven months.

Seven months, huh? Gee, what happened seven months ago? Oh, yeah, the president's approval ratings hit rock bottom.

As the economic recovery enters its sixth year, a number of factors help explain why many Americans don't feel better off: Income hasn't rebounded. Millions are working part time even though they want full-time jobs. It's taking longer to find work. People are still struggling with mortgage debt. Some feel down about the economy because of their political views. And most people don't feel free to spend as much as they used to.

To me, the most important reason is:

Most people are still earning less, adjusted for inflation, than before the recession struck at the end of 2007.

Is that all President Obama's fault? I don't think so. In fact, I think there's very little connection between who's president and the state of the economy. (I would argue that while Reagan and Clinton were mostly lucky, the two Bushes were mostly unlucky.) But it's hard to feel good about the president when times are tough.

Is this just temporary? Will the next president enjoy a healthier economy and better approval ratings?

Economist James Galbraith writes in Politico, "Why We Won't Get to Normal: Don't kid yourself. We'll never have a pre-2008 economy again":

Are we still in the world that existed from 1945 to 2007? Or have things changed in ways that make the record of those years much harder to repeat?

Galbraith lists "four broad reasons to fear that we now live in a rougher world—a world in which we can no longer expect the 'normal' times we have grown so used to": energy costs, the world situation, the digital revolution and the financial system.

Galbraith may be right, but things have a way of going in cycles. I'll bet that the next president, whether it's Hillary or one of her Republican opponents, will be present for another upswing and his or her approval ratings will soar. (Or, conversely, if the economy goes into another recession, a la George H. W. Bush, he or she may end up a one-term president.)

The moral of the story: presidents live, or die, based on the health of the economy. Is that fair? No, but it's true.