Honestly, I think people are giving Cambridge way too much credit.
I have seen enough overblown promises in the big data, AI, <insert buzz word> industry to know people just make things sound more innovative than it really is.
People seem to be equating a political profile and targeted advertising with a brain ray that makes people pull the lever for a funded candidate.
Just to take one high level example: Facebook was still "thefacebook" and closed to the public by the time George W. Bush was elected to the white house for a second term. How can we honestly winkwink/nudgenudge a "stolen election" at the feet of facebook or CA when clearly liberal politics were defeated in 2000/2004 with standard political rhetoric? Why are we giving facebook/CA credit for having so much political power?
I hate to use such a broad lens for the recent incident and I hope I'm communicating what I'm intending to here. I just don't see how somehow this incident "changed everything" or even changed much of anything when you look at the history how campaigns get people to vote for their candidate.
People don't want to hear this but targeted memes didn't make people anti-abortion or pro-nazi or whatever conserative boogey-man you pick. Conservative voters are people not a pathology. You may not like their views or the way they vote but this whole "people who don't think the way I do are brainwashed" thing has to go. You're buying that argument at your own peril because conservatives aren't going anywhere.
Pre-social media, this was easy enough: the people with different opinions were just less educated or less informed, and once they became informed they would hold the same views that we do. Social media changed all that by bringing those with different views into direct confrontation where you could immediately connect with someone with different views to your own and educate or inform them.
This fails to work. As soon as we try that, we quickly realize that those with other views are already informed and have just taken a different judgement. So we're left with the problem: either our views are wrong or their views are wrong. Deeply concerning as it's just as likely to be our own views. The only solution then is to shift the blame - it's not our fault or people with other views at fault: it's that there are 'evil actors' working to 'brainwash' people. Therefore our views are correct, and it's just people with other views who have been brainwashed. Simple and clean, no need for self reflection or difficult questions.
That's outside of this bigger experience we're all having about the necessity of respect towards those who hold different opinions and can demonstrate a systematic world view to get there.
So, it isn't to motivate somebody to vote for a particular candidate, but to not vote, or prevent the possibility of voting.
Target the opposition, if you will.
Though I still think it's necessary to fight the temptation to believe such a campaign is as easy or effective as our conspiratorial nature might want us to believe.
Together this means you can not only use laser targeted advertising, but show ads to one group you know will appeal, without a second group who would be put off by the message ever being aware of it.
There is also the potential to break rules on election advertising and false claims as the only people to see your ad are the small, well targeted group and an FB reviewer who is checking the ad against their own T&Cs, not the electoral rules of the country the campaign is in.
You could have some level of legal oversight (we've never had 100% perfect coverage) without eliminating the use of programmatic targeting.
It was targeted miss-information - directly at the people they needed to vote.