What i have been saying for days now.. SCL Group's Cambridge Analytica is the crux of it all. They shut down themselves, but also advertisers are leaving.
Cambridge Analytica was only formed in 2013.. it was to data mine and SCL Group are known to "shape elections" off their own web page. They are the center if you would to the election manipulation.. they were in charge of running experiments on Facebook for emotional feedback, once they established a baseline, they then moved in w C.A. to collect the data they could use to manipulate people REAL TIME.
Combined with the suppression of conservative news and opinion.. they controlled the narrative, thus controlling the election.