Several long winters ago, when President Obama was thunderously elected amid Messianic fervor, and much of the right was in the throes of apoplectic confusion, some liberal writers warned of a phenomenon among right-wing intellectuals, which they called "epistemic closure." The charge was that conservative thinkers had lost the ability to process the idea that the world of 2008 was not the world of the Reagan Era, and more generally to consider new ideas or, really, reality. The word "derp" entered our lexicon to mock forehead-slappingly stupid statements, defined by the liberal blogger Noah Smith as "the constant, repetitive reiteration of strong priors."

Liberal writers overstated the phenomenon at the time, and there was always a bit of shadow-boxing and concern-trolling there. But they did have a point. Still, even as they were making that point, the smartest writers on the right were already rising to the occasion. A flurry of innovative young writers like Yuval Levin, Reihan Salam, Ross Douthat, Tim Carney, and Avik Roy put out fresh, 21st-century ideas on everything from tax reform to health care to social mobility to poverty to curtailing the power of Big Business. Many of these ideas are now compiled in a seminal new book. And many of these ideas have been adopted by the most prominent GOP politicians and presidential candidates. Only with the right leader will the GOP truly embrace what's been called reform conservatism, but it's clear that the GOP is becoming the party of ideas again.

Meanwhile, two things are particularly striking about the current Democratic agenda. The first is that it's so tired. Raising the minimum wage, raising taxes on high earners, tightening environmental regulation — these are all ideas from the '60s. The second is that nobody on the left seems to be aware of it.

One of the most striking examples of this epistemic closure among liberal writers are their forays into "explanatory journalism." The idea that many people might like clear, smart explanations of what's going on in the news certainly has merit. But the tricky thing with "explaining" the news is that in order to do so fairly, you have to be able to do the mental exercise of detaching your ideological priors from just factually explaining what is going on. Of course, as nonliberal readers of the press have long been well aware, this has always been a problem for most journalists. And yet, the most prominent "explanatory journalism" venture has been strikingly bad at actually explaining things in a nonbiased way.

I am, of course, talking about Vox, the hot new venture of liberal wonkblogger extraordinaire Ezra Klein. It was already a bad sign that his starting lineup was mostly made up of ideological liberals. And a couple months in, it's clear that much of what passes for "explanation" on Vox is really partisan commentary in question-and-answer disguise.

And the troubling thing is, I don't think the people at Vox are even aware that that's what they're doing.

Consider this selection of Voxplainers on ObamaCare. "Millions of Americans are paying less for ObamaCare than cable"; "The best evidence we have that ObamaCare is working"; "Kathleen Sebelius is resigning because ObamaCare has won"; "The right can't admit that ObamaCare is working." (The URL slug on the last one: ObamaCare Derangement Syndrome.) Hmmm..

Or take another, related topic: Single-payer health care. What are the arguments for or against single payer? That's a complex topic! Thankfully Vox's Sarah Kliff, former health policy reporter at The Washington Post and a noted progressive, is here to explain. Her post on the topic — which purports to list the arguments against single-payer — does not mention the fact that cancer survival rates and other positive health outcomes are significantly higher in non-single-payer countries than in single-payer countries. It seems relevant. The point is not whether or not single payer is wrong, or that the cancer survival rate point is decisive. The point is that a prominent, talented liberal writer on health policy, asked to make an objective list of arguments against single payer, cannot do justice to the job.

Or take the alleged loss by the IRS — which imposes onerous archiving requirements on all large companies — of certain important emails related to the agency's targeting of conservative political groups. It certainly looks bad for the IRS. But it's really conservatives' fault, says Vox: The IRS scandal shows the IRS needs a bigger budget. Never mind the fact that the IRS already has a $2.4 billion IT budget and countless companies are able to archive emails with much smaller budgets, or that the IRS had a contract with an email backup company. Never mind that the argument for a higher budget is based on the notion that IRS applications rose dramatically before the scandal, which is, um, not true, even according to the liberal website Politifact. Again, the point isn't to litigate the IRS issue. The point is that Vox often looks more like a right-wing caricature of what a partisan media outlet dressed up as an explainer site would look like, rather than an actual explainer site.

There is no doubt that Klein and Vox are earnest. They are not engaged in some vast conspiracy to deceive the American public and surreptitiously plant liberal ideas in Americans' brains. Instead, Vox just contains a disturbing amount of, well, derp. (It's great at sports explainers, though!)

Another symbol of growing epistemic closure on the left is The New Republic, which, under new ownership, has gone from being an idiosyncratic magazine critiquing liberalism almost as often as endorsing it to becoming a liberal mouthpiece, and now has decided to get into the explanatory journalism game. The name of their new vertical? "QED." The jokes write themselves.

Increasingly, liberal writers have been drinking their own Kool-Aid. They really believe they are the "reality-based community." When they talk about conservatives they respect, they qualify their praise with "The smart conservative so and so..." — with such "he's one of the good ones" asterisks betraying the wholly unwarranted assumption on the left that the vast majority of conservatives are crazy, stupid, or both.

And yet, liberals themselves are very rarely capable of passing an Ideological Turing Test. They believe not only that an honest evaluation of the world lines up with their worldview (everyone does, to some extent), but have also forgotten how to differentiate between the honest evaluations and their worldview, or that doing so is even possible, or that their worldview is based on very idiosyncratic moral priors.

Back when epistemic closure was more salient a problem on the right, the liberal writers who pointed it out were mostly genuinely concerned: A healthy polity needs a healthy intellect on both sides of the aisle. The left needs an intellectually vigorous right, and vice versa — so get your act together.