The Markup put their Citizen Browser project to work in the Georgia runoff election to see what happened when Facebook started re-allowing political ads. Newsfeeds got more partisan, misinformation re-appeared, and conservative news sources like Breitbart dominated. Democrats spent the most, but conservative news posts produced the most engagement.
A few things to note about this story: first and foremost, none of it is surprising. We know already that conservative news and opinion dominate the social network — most likely because the mechanics of Facebook favor outrage and conservatism is reactionary by definition. We also know that tweaks to the product that would reduce this effect are regularly shot down by politically aligned executives.
The sample size for the research for this story is also small, and under-represents Latino and self-identified Trump voters, as they spell out in the article. However, since Facebook doesn’t allow researchers access to their data, it’s the best we’ve got. This is good, important work from The Markup.