The discovery that social media, as currently implemented, is in the process of annihilating rational discourse is the single most important discovery of this election cycle. Possibly of the last decade.
Even now, because of this problem, there is no longer agreement on many basic facts. The notion that a people so polarized on basic truths will ever be able to function together democratically is what is utterly naive. Under such circumstances, ultimately one side will have to force its view of reality on the other.
Indeed it may not be a coincidence that the sudden success of extremists parties in the west, driving voters to vote so conspicuously against their own self interest, corresponds almost exactly to the emergence of social media in general and facebook in particular.
What is naive is the belief that truth will somehow win out when the bulk of mankind sees the world predominantly through a facebook feed that explicitly selects for spectacular self confirming nonsense algorithmicly suppressing anything unpleasant to know.