I'm sure you've all already heard snippets of this, including various aspects of how it can be effected technologically, to what degree and to what ends. I think, though, that this is a good summary of the topic to date. It's been a long time from when the first opining of "I'll believe it when I see [hear] it" to where anything similar has any real relevance.

(My sons and I have had some interesting discussions about "Black Mirror" style completely fake candidates for high office, ones who could be presented through holograms of invented personae, created from scratch by experts on attracting voters - that in turn, optimized by where political statisticians have learned they're most needed per redistricting studies.)

And who can actually care anymore about what "camps"are seeking in the sense of loyalty or even self-interest, for that matter? Experts capable of coming up with electorally marketable images are no different from traditional mercenaries in that they're in it for pay. Have you not heard of such mind-benders working for both candidates in a given election? Ultimate mercenaries only without lives at stake.

Teasing aspects of promotion down to irreducible, UN-fakable aspects, personally, I have only come up with the "IRT" (in real time) factor of influence. I.e., how the candidates - real or fake or some combination - respond on the spot to questions, insults, challenges. That (even if teamwork is behind a mechanically produced voice) still seems hard to fake while an audience is making judgment calls and establishing preferences.

Not counting how much responses are colored - and deeply, IMO - by the influence of favorite pundits, televised or in next day's (or next sermon's) OP-Eds. How many people are still capable of "the courage of their convictions" - that is, even arriving at judgment calls all by themselves? I.e., without exposure to explications of what they've just witnessed, from "higher ups" they trust more than themselves?

Social scientists have already given us so many concrete examples of how witness bias can distort memories much less convictions!

But how do we really know anything anymore?