That's actually a good question that needs its own thread.
Maybe even more than one thread.
#1 biggest issue to me is the FAILURE of Big Media to be unbiased, or, even more so in the Trump years, nonpartisan.
They don't realize it yet, but they broke themselves over this. Everyday, more people become convinced of their horrible bias, and their reporting as actual news—events that happened—and not some narrative the Left is pushing.
#2, and it relates to #1, is the glee with which that same media wedded themselves and their stories to the Deep State—something they used to be against.
#3. With so much fake news out there, it gave the opportunity to alternative sources of news, such as Talk radio, conservative newspapers/magazines and then Fox News. This is the environment Free Republic was born in. The three sources I listed were pretty accurate, and were not as biased as some have become since.
#4. The growth of the Internet led to many sites, Left and Right, that were very partisan, and reported events, even the same event, far different from each other.
But the far Left and Left biased sites got credibility and support from the Mainstream media, while the Mainstream excoriated Fox News and talk radio as horribly biased to the Right. So pretty soon you had reporters, writers, and producers who moved back and forth from one Leftwing environment to the other, meaning writing an article in Vox, then Salon, then posting on Democrat Underground or reddit/politics, then another article on the New York Times, the Atlantic, then Mother Jones, Tweeting SJW nonsense and anti-Americanism on Twitter, then working for ABC News, then appearing on a panel on MSNBC, and back again from the multimega corporate news behemoth to the little whacko Antifa website.
They also migrate between democrat politics and government to the media and back again. Seriously, George Stephanopolous as a legitimate news reporter, given the DEEP political world he came from?
This migration of "journalists" is ruining them across EVERY outlet.
#5. Now all this #4 business was taking place as #1 and 2 was intensifying.
#6. Posters feel like their political ideals and stories are deliberately lied about, so it becomes easier to believe lies from the Right.
So here we are.
But I do blame today's journalist for starting this whole thing. The falsely claimed the virtuous position of non-bias, and then chose to deliberately go full board onto social justice at all costs, including, and especially, the truth.
Individual responsibility begins and ends with the individual. Nobody, including the MSM, makes conservatives post fake news.
Plus, for conservatives, a lot of the news is pretty bleak.
So, people grab onto anything that confirms there own bias, and don't stop to apply a reasonableness test, or critical thinking.
And that bothers me the most, the entire left, and now an increasing amount on the right, have detacted themselves from reality.