I think the issue is that to a general audience it's something that you can't just say in passing with a noun phrase without establishing that you're talking about this bias first, but if I had to produce a phrase then it would probably be "the less-politically-educated" or something, since obviously there are lots of people with political education who are contributing to problems in The Discourse, but the people who just hold up MBFC like it's a cross to repel the vampire of radicalism are, in my opinion, mostly the kind of people who have very little political education and just consume a lot of corporate news or NYT (or some equivalent). The ones with an education will more consistently present (hackneyed) arguments or actual articles.

I could be wrong though, it's just the impression I get.