The problem here, as is the root of almost all the problems we face in society isn't Cambridge Analytica. The problem is people lack basic critical thinking skills and the capacity to make good decisions.
> It's deliberate manipulation to create distrust of government institutions.
Nobody with any knowledge of history or good sense trusts any government institution.
>It's the destruction of civil society and civil discourse for the purpose of winning an election.
This would require having a civil society filled with civil discourse to start out with, which we didn't (and don't) have.
The simple, irrefutable truth is that governments and those in other centers of power have been using propaganda to control feeble minds and society at large since Woodrow Wilson founded the first official state-run propaganda machine (the CPI) over a hundred years ago.
Everyone is trying to find a "reason" that people rejected "traditional American institutions" and the establishment candidate (Hillary Clinton) in favor of a classless, boorish carnival barker in Donald Trump. They point to the evil Russians, or the dastardly villains at Cambridge Analytics, because they don't want to accept that "traditional American institutions" have been utter garbage for decades. They don't want to accept that many, many Americans are simply rejecting the status quo. Americans may not be smart or informed enough to know exactly what is wrong with "the system", but they know its horribly broken, it doesn't work in their interests, and many of them are reflexively rejecting that system. They aren't rejecting it because of the Russians, or because of some Twitter trolls, or some facebook ads - they are rejecting it because they have seen their standards of living plummet over the last few decades while those at the upper echelon of society have gotten fabulously wealthy. They are rejecting it because so many people are one illness or accident or lost job away from being homeless. They are rejecting it because they have seen (and continue to see) a race to the bottom for working people while the "elites" push for open borders and a massive influx of cheap labor that will make their lives even more difficult.
So keep on crying about the evil Trump and the dastardly Russians, and whatever other phantoms you invent to explain away the growing national discontent while keeping your head in the sand about the real problems we have.