In 2012, CNN's Candy Crowley moderated the second presidential debate between Barack Obama and Mitt Romney. Afterward, she explained why climate change never came up.

I had that question for all of you climate change people. We just, you know, again, we knew that the economy was still the main thing so you knew you kind of wanted to go with the economy.

This moment became something of a legend among, uh, "climate change people," as it showed so clearly the way CNN understands the issue: as a boutique concern of one faction of the left, namely environmentalists. It's not a "main thing" like the economy, and certainly not part of the discussion of the economy.

Public awareness of climate change has come a long way since then, and so has the Democratic Party. CNN, it seems, has not.

CNN shows it still doesn't understand climate change or take it seriously

In Tuesday's Democratic primary debate, the candidates mentioned climate change several times unprompted. Martin O'Malley, Bernie Sanders, and Hillary Clinton all touched on it during their opening statements. O'Malley and Sanders hit it again in the context of national security, and Clinton when defending herself from the charge of flip-flopping on the Keystone XL pipeline.

But there was no question on climate change until the final segment of the (gruelingly long) debate. O'Malley tried again to bring up a "green revolution" in energy, and Cooper cut in with this segue for the ages:

We'll talk more about environmental change and climate issues coming up. Some of the candidates have tried marijuana, as have probably everybody in this room. Does it influence their views on legalization? Find out that and others ahead.

"Environmental change and climate issues" ... something, something ... weed! Sounds like he can hardly wait.

After the break (during which, I thought it was fairly clearly implied, Webb threatened to walk off if he didn't get more time), Cooper went to a vapid meta question about who is and isn't an "insider."

Then Sanders tried yet again to bring it back to climate change, and Cooper relented.

Who finally got to ask the question? Just as CNN had a Latino anchor ask about immigration, a woman anchor ask about paid leave, and an African-American kid ask whether black lives matter, it gave the climate question over to Anna, a young white woman who looked every bit the liberal arts student. That, you see, is a "climate person."

And then there was this maddening segue from Don Lemon: "Please tell Anna how you would protect the environment better than the other candidates on the stage."

There is the key piece of CNN's understanding of climate change: It is an "environmental issue," of concern to environmentalists. As a special interest issue, not a "main thing," it is reserved for the end of Democratic primary debates, so that candidates can pander to their base, but is not worthy of presidential debates.

And so the question finally came up. O'Malley gave a great answer. Then Cooper, who had basically been excluding Webb from the debate all night, finally found a question he values low enough to give Webb a little time to filibuster on it.

Webb offered a pointless ramble about all-of-the-above energy and a gratuitous swipe at Obama's historic climate pact with the Chinese — a take on climate change that is woefully out of step with the current Democratic mainstream. It's more like "conservative Democrat from purple state, circa 2006," which these days has become the moderate Republican take on the issue. Either way, it was an obvious waste of time.

Then came rushed answers from Sanders and Clinton and the issue was gone.

The village understanding of climate change remains dismal

In all these small ways, CNN revealed an understanding of climate change that is about 10 years old. But it remains frozen in time, not only at CNN but in much of the Village, the clubby circle of Beltway players, journos, and pundits who watch one another on Sunday cable talk shows.

To them, it remains an "environmental" issue, despite the fact that it involves terrible threats to human economies, health, and geopolitical relationships. It remains a "base" issue on the left, despite the burgeoning involvement of cities, new industries, investors, entrepreneurs, and civic groups. It remains a "young person" issue, despite warnings that markets are already at risk, today, from massive unpriced threats.

And above all it remains a peripheral issue, not something the average person really wants to hear about.

At least Crowley had the economy as an excuse (despite her ignorance of how intimately climate change is related to the economy). What did Cooper think people really want to hear about? Who's "electable." Who flip-flops. Clinton's friggin' emails.

These are the kinds of things that give people like Cooper the optics of being "tough" — calling out seeming contradictions or asking loaded character questions. What's really tough for someone in Cooper's position is stepping outside the self-absorbed world of DC political journalism to assess the issues on their real-world importance. In his fealty to the comfortable worldview of the cosseted US political class, Cooper was anything but tough. He was a perfect puppy dog.