But much of the news on Facebook was fake, media watchers pointed out, compromising the platform as well as confidence in the media. One local official shared news on Facebook with headlines such as “Hillary Clinton Calling for Civil War If Trump Is Elected” and “Pope Francis Shocks World, Endorses Donald Trump for President,” said Joshua Benton, director of Harvard University’s Nieman Journalism Lab. “These are not legit anti-Hillary stories,” he wrote in a blog post. “These are imaginary, made up, frauds. And yet Facebook has built a platform for the active dispersal of these lies — in part because these lies travel really, really well.”

Source: How Trump bypassed hostile media to deliver his message
As well documented at this blog on social media propaganda, fake news is a serious problem on FB. It is so serious that I have now severely curtailed my use of FB.
Facebook has become a swamp of misinformation and propaganda about numerous topics (not just politics).
Fake news is not likely why Trump was elected. The issues were far deeper than Trump versus Clinton, as at the end, the Republican’s had a

• Majority of state governorships
• Majority of state legislatures
• Majority in the US House
• Majority in the US Senate
• Presidency

Based on my experience unsuccessfully trying to help my legislators create fixes to broken parts of ObamaCare (families having to pay $2,000 to $3,000/month or more is not sustainable) is that my legislators, all Democrats, stopped listening to constituents. They, and their Party, became self righteous, arrogant and elite, unwilling to listen to the commoners – because the Party already knows what is best. Literally that is the message delivered by my own elected representatives: they made clear they had no interest in listening to constituent input.
This election was a vote against this arrogant elite who had stopped listening.
Will the Republican’s govern differently – and listen to constituents – or will they be just as arrogant (probably) and thrown out in the next election? Who knows, but we can be sure that social media will contain even more false news stories and propaganda posters creating facts out of thin air!
Disclosure – I am not a member of any political party and I did not vote for Trump.
(Off topic but … the best step for the Democrats would be to start listening to their customers AND their competitor’s customers. Initial news reports suggest the Democratic Party elite are mostly listening to each other – which means they still do not get what the problem is nor how to fix it. Indeed, The Intercept has written an article saying much the same thing – the party elite are blaming everyone but themselves.)