But journalistic groupthink is a symptom, not a cause.

From The Media Bubble Is Worse Than You Think by Jack Shafer and Tucker Doherty

This article provides some empirical underpinnings of my thesis that the mainstream media is so biased to the left because the media is located in large urban locations where the dominant ethos is left. I discuss the idea and some of its broader implications in The effect size from their perspective is that much smaller than from yours.

Shafer and Doherty:

The answer to the press’ myopia lies elsewhere, and nobody has produced a better argument for how the national media missed the Trump story than FiveThirtyEight’s Nate Silver, who pointed out that the ideological clustering in top newsrooms led to groupthink. “As of 2013, only 7 percent of [journalists] identified as Republicans,” Silver wrote in March, chiding the press for its political homogeneity. Just after the election, presidential strategist Steve Bannon savaged the press on the same point but with a heartier vocabulary. “The media bubble is the ultimate symbol of what’s wrong with this country,” Bannon said. “It’s just a circle of people talking to themselves who have no fucking idea what’s going on.”

The map at the top of this piece shows how concentrated media jobs have become in the nation’s most Democratic-leaning counties. Counties that voted for Donald Trump in 2016 are in red, and Hillary Clinton counties are in blue, with darker colors signifying higher vote margins. The bubbles represent the 150 counties with the most newspaper and internet publishing jobs. Not only do most of the bubbles fall in blue counties, chiefly on the coasts, but an outright majority of the jobs are in the deepest-blue counties, where Clinton won by 30 points or more.

But journalistic groupthink is a symptom, not a cause. And when it comes to the cause, there’s another, blunter way to think about the question than screaming “bias” and “conspiracy,” or counting D’s and R’s. That’s to ask a simple question about the map. Where do journalists work, and how much has that changed in recent years? To determine this, my colleague Tucker Doherty excavated labor statistics and cross-referenced them against voting patterns and Census data to figure out just what the American media landscape looks like, and how much it has changed.

The results read like a revelation. The national media really does work in a bubble, something that wasn’t true as recently as 2008. And the bubble is growing more extreme. Concentrated heavily along the coasts, the bubble is both geographic and political. If you’re a working journalist, odds aren’t just that you work in a pro-Clinton county—odds are that you reside in one of the nation’s most pro-Clinton counties. And you’ve got company: If you’re a typical reader of Politico, chances are you’re a citizen of bubbleville, too.

[snip]

The result? If you look at the maps on the next page, you don’t need to be a Republican campaign strategist to grasp just how far the “media bubble” has drifted from the average American experience. Newspaper jobs are far more evenly scattered across the country, including the deep red parts. But as those vanish, it’s internet jobs that are driving whatever growth there is in media—and those fall almost entirely in places that are dense, blue and right in the bubble.

[snip]

In a sense, the media bubble reflects an established truth about America: The places with money get served better than the places without. People in big media cities aren’t just more liberal, they’re also richer: Half of all newspaper and internet publishing employees work in counties where the median household income is greater than $61,000—$7,000 more than the national median. Commercial media tend to cluster where most of the GDP is created, and that’s the coasts. Perhaps this is what Bannon is hollering about when he denounces the “corporatist, global media,” as he did in February at the Conservative Political Action Conference. If current trends continue—and it’s safe to predict they will—national media will continue to expand and concentrate on the coasts, while local and regional media contract.

The maps are striking, especially the one for internet media:

Click to enlarge.