Much of Facebook's dilemma
is due to their attempt to interfere as little in other people's 'free speech' as possible, combined with a healthy input of profit motive from their corporate model. The lesson to draw here is not that Facebook was a f-cist supporter of the Trmp, but that the Trmp organization realized what they could get away with and played Facebook like a cheap violin, and the Hillary organization did not take the same advantage. Whether this was moral sense or a lack of tech savvy is prolly debatable. But consider how easy it was to gain access to John Podesta's email.

Anyhow, more on ranked-choice voting from ballotpedia.