MIT have done a study on right-wing media in the run up to and around the 2016 election. Interesting stuff. Talks about how Breitbart set the media agenda and other MSM followed their lead meaning disinformation came out of the internet backwaters into the mainstream where, of course, it gains a veneer of credibility.
Our own study of over 1.25 million stories published online between April 1, 2015 and Election Day shows that a right-wing media network anchored around Breitbart developed as a distinct and insulated media system, using social media as a backbone to transmit a hyper-partisan perspective to the world. This pro-Trump media sphere appears to have not only successfully set the agenda for the conservative media sphere, but also strongly influenced the broader media agenda, in particular coverage of Hillary Clinton.
Study: Breitbart-led right-wing media ecosystem altered broader media agenda
www.cjr.org/analysis/breitbart-media-trump-harvard-study.php