Most political discourse is epideictic, which is to say, it’s about credit and blame. For instance, whenever we get an economic downturn in this country, the party not in the White House will blame the President, and the President and his supporters will blame his predecessor, whose bad policies have finally come home to roost, or a recalcitrant Congress, or bad judicial decisions, or whatever. If there’s an economic upturn, the President will take the credit, while his detractors will insist that he is merely benefitting from the wise decisions of his predecessor.
The problem with these disputes is that they are almost always irresolvable, and they’re irresolvable for two reasons. The first is that political and economic circumstances are so immensely complex, with so many forces mutually interacting, that it is simply impossible to know which ones have the greatest influence. And our inability to understand that complexity is related to a second factor: we can’t rewind the tape of history. We don’t know what would have happened if the former President had pursued policies similar to those of the current President, or if some particular judicial decision had gone the other way, or if Congress had passed the bill that the President wanted to have passed. Understanding how our ungoverned and ungovernable world works is not something we can do in laboratory conditions; controlled experiments are, and always will be, beyond our capabilities.
But political partisans don’t understand these factors, or refuse to consider them. They construct explanatory schemes that reinforce their political preferences, and then decry all alternative explanations as fake news. And this behavior will continue no matter what Facebook does to monitor the factual status of political statements on its platform.