In the never-ending philosophical battle over whether social media is good or bad for democracy, the anti-Twitter cohort just scored a big point: According to a fascinating audit of Congressional Twitter accounts by New York Magazine’s Dan Amira, our politicians overwhelmingly follow only people and news sources that align with their views.

This is Twitter.

Republicans follow Speaker Boehner, the Heritage Foundation and the House Conservative caucus. (@WhiteHouse doesn’t even crack the top 20.) Democrats keep closer tabs on the Democratic caucus and Rachel Maddow more than their colleagues across the aisle.

The problem with all this, of course, is that it creates what some theorists term “echo chambers” -- comfortable bubbles of information that reaffirm our preexisting beliefs and tastes. The Internet is infamous for this: Netflix shows you films based on what you’ve watched already, for instance, and Google will tweak your search results to anticipate what you’re most inclined to click. Twitter tailors its recommendations to mirror the people you follow already, which might help explain why our Congressmen (or more likely, their staffs) tend to follow along party lines.

These little personalizations are often convenient from a consumer standpoint. But they prove trickier when we get into big-picture questions, like how information and opinions percolate online. If I follow only liberal media outlets and personalities, for instance, I’m probably only getting the liberal perspective on a huge variety of issues. That makes it more likely that I will (1) believe more people share the liberal perspective than actually do and (2) fail to understand, or even engage, conservative positions and arguments.

In short, the political discussion gets even more polarized and less meaningful than it was already.

Communications research bears this out. In 2010, Sarita Yardi and Danah Boyd analyzed the tweets around the murder of George Tiller, a late-term abortion doctor, and found that Twitter-users were generally more likely to converse with people who shared their abortion views. A similar study out of Nova Scotia’s Dalhousie University came to the same conclusions in Canada.

But there are a few caveats to all this: Echo chambers are porous, and they aren’t exactly uniform. Yardi and Boyd note that a diversity of viewpoints exist, even within Twitter’s politically “homogenous” clusters. And just because people tend to follow like-minded tweeters doesn’t mean they don’t engage with others; both the Yardi/Boyd and Dalhousie studies concluded that there’s plenty of “cross-talk” on Twitter and, maybe more importantly, the potential for greater cross-ideological discourse, at least among users who seek it out.

The New York Magazine piece wasn't all bad news, however. It named The Fix as one of the five most followed accounts by Members of Congress. There's just no accounting for taste.